WAVE Ricardo Software
 

Hello, we are searching for any information on the web about the Ricardo Software named WAVE. This sofware is a 1D engine simulator.

Thank you for your Help.

CED

Re: WAVE Ricardo Software
 

Have you looked at Ricardo's homepage? If not, go to (se menu above) Resources/Homepage Database/Companies. There is a link to Ricardo there.

Re: WAVE Ricardo Software
 

Ricardo is a small company and the guys who developed the software don't have credentials just like the case of software Star-CD. Wave is a software for small people (low level engineers) or the beginners in compressible flow. Kiva is comparatively better hydrodynamics software developed in National Laboratories by people with good academic credentials but still more work needs to be done. Fluent is comparatively better than Star-CD because Fluent gives better results than Star-CD. Star-CD may be easier to converge than Fluent but it doesn't mean the results are more satisfactory. So if you can't get hold of any software developed in National Laboratories or NASA then I would recommend you to stick to Fluent. Something is better than nothing. Special softwares are developed to serve special purposes which have great significant importance in science and engineering but we may not have access to it. We have to learn to live with this limitations. We can't do anything about it.

Re: WAVE Ricardo Software
 

Eh, you're comparing apples and oranges. Wave is a highly specialised 1D gad-dynamics code used solely to design engines. It is not a CFD code and it can of course not be replaced by a general purpose CFD code, like the ones you are mentioning. In fact I even think that Wave can be coupled to, for example, STAR-CD, if you want to model some components using CFD.

Re: WAVE Ricardo Software
 

I have no idea what made you compare WAVE with general purpose CFD codes like FLUENT or STAR-CD. These are two completely different groups of products which have little or no similarity at all. I am a WAVE user and I object to the saying WAVE is for 'small people(!)'. Have some respect for people who do not follow the same methodology as you do.

WAVE is a 1D gas dynamics software used mainly to model internal combustion engine performance and acoustics. It is a widely accepted software for powertrain analysis not only in the US but worldwide. It is true that 1D formulation has a lot of shortcomings over 3D formulation but this does not mean it cannot deliver valuable information about the flow in general.

If you do want to compare WAVE do that with a similar product such as GT-POWER which is another powertrain analysis code based on 1D assumption. Both these codes have interface with 3D codes such that the 3D code output may be used as input to the 1D model and vice-versa. WAVE is connected to VECTIS and GT-POWER is connected to STAR-CD.

Both WAVE and GT-POWER have a nice web site. Please visit www.ricardo.com and www.gtisoft.com for detailed information.

Re: WAVE Ricardo Software
 

Didn't the companys designed their diesel engines using WAVE, STAR_CD or whatever crab and got penalty of one billion dollar for producing engines with emissions problems? Then how can these softwares be reliable! You are not in USA and you are not quite aware of what is happening. GM already started spending about one billion dollar per year until 2004 to develop engines with less tailpipe emissions, better performance and meet fuel economy goal. Daimler-Chrysler and Ford Motors are also spending billions of dollars for research to come up with solutions to meet future stringent emissions goal. We are seeing with our own eyes the consequences of using wrong softwares. This is not a child's play anymore. So now you can guess where small companies who developed STAR-CD or WAVE stands!

Re: WAVE Ricardo Software
 

Usually I would let baseless statements go unanswered, since this is a forum for CFD and related issues. However, I feel it is necessary to respond to this thread.

(1) the size of a company is not an indication of the quality of its output (design, software, analysis, etc.). In fact, I can argue the exact opposite -> a small company survives only by being at the forefront of technology and by working hard. In contrast, many (not all) people who work for giants spend most of their time in the halls of the buildings with their coffee mugs in their hands and talking BS. I have worked for the smallest to the largest of them - I know!

(2) I have not used any commercial codes so I am not supporting one vs another. But the assumption that you will have all your problems solved using the most complicated 3D code does not correspond to reality. See the following:

I understand that WAVE is an acoustics code. Flow in engines is for the most part incompressible - or low Mach number compressible. To the second order in the Mach number you can obtain accurate solutions by the assumption of incompressibility. What does this mean? This means that the effect of pressure is felt everywhere instantaneously, because (again up to the leading order of the Mach number) pressure variation depends on time and not space. By extension, it becomes obvious then that, for the bulk of the flow, acoustics in the engine is 1D. The 3D effects are secondary in nature (you have much more serious issues to contend with than the three dimensionality of the acoustics in engines).

So, what does this tell you about a person who uses a 1D code for engine acoustics analysis vs. a full blown CFD? I'd say, if the code is used in the proper range, the first guy knows what (s)he is doing. I cannot be impressed by the CFD user who believes in brute force and expects the colored results to somehow magically help him understand the flow physics!

As for the tremendous loss engine companies are suffering from -> the conclusion that it is the fault of the CFD codes (or developers) and not the users is equivalent to blaming the gun itself for the action of the murderer (sorry I could not think of a better analogy)! Somehow you seem to be under the impression that people who work for these big engine companies know what they're doing (know their physics, can interpret data and not just show colors to dazzle their bosses, and more importantly can provide better solutions) Absolutely wrong: I have seen an internal report by an engineer for an american auto company who did a parameteric study using CFD, varying Reynolds number and viscosity as two parameters of interest! They also concluded that viscosity is as important a factor as the Reynolds number! (That is if you fixed the Reynolds number and changed viscosity you would get different results, blah blah) What a pile of garbage - not even the boss of this engineer (with a PhD) objected to the absurdity of the choice of parameters and the conclusion. It tells you that this guy doesn't know the very basics of fluid mechanics and you expect reduced emissions coming out of this particular center of excellence?

Let's be a little more prudent in our observations and conclusions of the reality.

Adrin Gharakhani

Re: WAVE Ricardo Software
 

National Loboratories and leading universities are putting their heads together to come up with solutions to meet future stringent emissions problems in USA. WAVE or STAR-CD softwares are like mole-hills compared to mountain. I am repeating again that this is not a child's play anymore. You are probably trying to build a mole-hill with sand that has not chance of survival.

Re: WAVE Ricardo Software
 

In defence of both companies that you are describing as 'small fry'. Admittedly I have worked for/with both of them so perhaps I am biased.

One, Ricardo, has been in the internal combustion engine development business since approximately 1920, well before Los Alamos was a twinkle in Robert Oppenheimer's eye. Now 70 years developmental experience may not mean anything to you but in the industry they are well respected. They probably, as an organisation, know a little bit more about the workings of the internal combustion engine than the average national lab.

As for STAR-CD, CD its parent has developed Speed which was funded by the European auto industry again a not insignificant level of experience. As for them not having credentials, surely coming from Imperial College for finite volume CFD codes is the credential.

I would be interested to know what 'better results' means ? Are you saying that on the same grid using the same boundary conditions, similar if not exactly the same numerical scheme and with the level of convergence equivalent (taking into account the different definitions used) you achieved fundamentally different results? If so, I would have to say that one of the codes had a bug or that the comparison is flawed in some other way. The various commercial codes have their many strengths and weaknesses but should produce comparable results if compared correctly.

Finally by the standards of GM/Ford .... Fluent (Aavid) is a tiddler. Does this mean that GM should only be using software developed at their own research labs. Competency and size are not one and the same thing.

Re: WAVE Ricardo Software
 

(1). I don't know what to say about the issues here. (2). But I think, I need to point out something. When the name of the code is mentioned, when the name of the company is mentioned, somehow, it becomes more important than the CFD itself. (3). I think, in the IC engine design, flow through the inlet manifolds and the exhaust manifolds can have significant effect on the flow through engine, especially the multi-cylinder engine. So the length has to be computed based on the wave equations. There are books on this issue in great details. (4). There are also other important factors which affect the design of the engine itself, such as the fuel injection , the mixing, the way the flow entering the inlet port, the flow motion through the valve, the valve timing, the valve timing control as function of speed, the induced flow in cylinder, the flow rotation, the tumbling, the spark plug design, the heat range and heat transfer, the cylinder head design, the effect of turbulence on the combustion, the pre-ignition, the lean-burn design, the design of catalytic converter, the control of the catalytic converter,..... (5). I think, the traditional 1-D tools is o.k., but it can provide the overall performance model, with a lot of empirical data. The Star-CD although has the tradition from the Imperial College, is still far from providing the answers to the above design problems mentioned above. The nice thing about the Fluent is its unstructured mesh and refinement capability. But that alone, is not going to solve the problems. (6). I would say that it is going to take a lot of hard work to make progress in this field. This is because it is hard to make detailed measurement inside and outside the engine. Hopefully, the billion dollar project will first make the detailed flow field available first, and thus provide the information needed for creative new aproaches or design. Without such detailed information, trial-and-error approach is not going to solve these problems effectively. (7). It is not the codes which keep the company alive, I have seen 40 years old company disappearing, not to mention a company with over a hundred years of history, which also has disappeared recently. There is no question about the ability of these companies to design the product, the issue is can they design the product to meet the future standards and be able to say why at the same time. (8). Naturally, the key issue is in the fluid dynamics. And I don't think the traditional 1-D code will add any new information to the understanding of fluid dynamics, not even the current version of commercial CFD codes.

Re: WAVE Ricardo Software
 

Hi all,

We are currently comparing StarCd and Fluent for unstructered grids and I am extremely interested in your statement that Fluent is better than Star. On what do you base this statement? Which benchmarkcase have you simulated?

Re: WAVE Ricardo Software
 

(1). We are happy to learn that you and your company are taking the serious approach. (2). I can only share with you my experience in the industrial use of CFD. (3). The mesh independent solution is never resolved in industries, because it is not practical. It takes too long. (4). The solution convergence issue is never resolved, because in industries, they don't have a lot of money to spend. The solutions used in design are most likely non-converged solution. (If a case requires 80 hours to reach convergence, by just stopping the calculation at 40 hours will move the project ahead of time and there will be no problems with milestones to meet.) (5). The mesh is routinely optimized to give better solutions. If you can't refine the mesh to improve the solution, you find the mesh which can give you the better solution. (6). These are fairly common in industries, because the user is not the developer. So, he is not emotionally attached to the codes or solutions. And in many cases, he is not the one who is using the solutions. So, he does not care. (7). So, in the industrial society which is always looking for ways to cut costs, time, nothing can stop it until something bad happens. In other words, the industrial society prevents the proper use of CFD in industries. (The code testing at the user's site is already too late, from my point of view. The code should be in perfect condition to solve the user's problem when it arrives at the user's site. Otherwise, it should be returned. This is still my personal opinion. Believe me, it can be done.)

Re: WAVE Ricardo Software
 

Convective Heat Transfer from Hydrocarbon Flames

In internal combustion engines, a primary cause of low thermal efficiency is the heat transfer from the combustion gases to the walls of the cylinder during combustion. This research is directed toward two methods for controlling the convective heat transfer from such flames. The first method uses an electric field to force charged particles generated within the flame away from the nearby wall. In moving away from the wall, the particles thicken the wall boundary layer, thus reducing the wall heat transfer. The second method of control is to produce a tangential velocity over the wall surface with an external jet of air, thus moving the flame away from the wall. The objective of each of these studies is to reduce the wall heat transfer. Incorporating these techniques within the combustion chamber of internal combustion engines will significantly improve the overall efficiency of these engines.

Increasing the strength of swirl generation by tangential jets can reduce screeching noise in an engine. Can 'WAVE' software handle this kind of convective heat transfer and acoustics problems? I guess not! I have already mentioned earliar that I am a novice in CFD and am trying to learn.

Re: WAVE Ricardo Software
 

Fluent uses finite element method which is comparatively more matured method. Fluent usally is harder to converge for a given flow of interest but if you can converge it it will give you better results than STAR-CD. Try it yourself and let us know the results. Structured-based meshes are simpler and easiar to converge than unstructured meshes. Nowadays, even NASA is more interested to develop softwares using structured based simpler method. I really don't trust commercial CFD softwares that much but if I badly need to use a commercial software then I would stick to Fluent.

Re: WAVE Ricardo Software
 

Both Fluent and Star use Finite-Volume on unstructured grids.

Re: WAVE Ricardo Software
 

Yes! Both Fluent and STAR-CD use the finite volume approach and, in fact, STAR-CD was the first successful commercial code using unstructured mesh topology with finite volume approach.

CFD covers wide range of topics and CFD results strongly depending on the PHYSICAL modelling of things like turbulence and combustion - both topics have been attracting the attention of many leading scientists. If the physical models do not reflect the reality accurately, one should not expect the ACCURATE CFD results - I think many experienced CFD engineers are aware of this.

WAVE and GT-POWER are very useful specialised software and 3D CFD codes and these codes can compliment each other nicely.

Ricardo & WAVE
 

I am the business development manager for Ricardo Software. Please find the information below in response to some of the questions/points raised in the messages posted.

Ricardo is an engine engineering consulting company with operating offices all around the world including 3 in the US. We now have 1300 employees, the majority being engineers holding advanced degrees. We have been working on IC engines for over 85 years, so we are very experienced in this field. Among our contributions to the development of the IC engine that are part of our everyday life I can quote the definition of the Octane rating scale for fuel (the number you see at the gas station). We have developed a line of specialized CAE software tools (including WAVE) for the design of IC engines and specific engine components (such as the piston, rings, cams, ...). We use these tools regularly in our consulting activity. These CAE programs are also widely used by the rest of the IC industry. WAVE is used at GM and DaimlerChrysler (two companies mentioned in the messages) as well as at most other OEMs and component suppliers worldwide. Interestingly we have also been approached by very prestigeous Research Labs in the US with the request of supplying our codes for research purposes (as part of our University Grant program).

Undoubtely there are advantages to linking 1D engine cycle simulation softwares (such as WAVE) to 3D CFD codes. WAVE has been linked to our own 3D CFD code VECTIS for the past 3 years and within a couple of months the interface between StarCD and WAVE will also be released.

If you need more information regarding Ricardo or WAVE please visit our website at www.ricardo.com or feel free to contact me directly.

Best Regards

Dott. Enrico Bradamante

voice: +1 (630) 789 0003 x 214 e-mail: EBradamante@ricardo-us.com

Re: Ricardo & WAVE
 

I don't exactly buy what you are trying to say. Recardo have hands on experience in designing and testing because the company has been working with the IC engine over and over again similar to Proving Ground type work of an automotive company. You are saying that Recardo is a consulting firm working for decades developing engines. Then tell me why are the engine companies getting so much penalty for producing engines with emission problems? What does it prove! Recardo or other consulting companies don't have the advanced technology to confront future stringent emissions requirements. Why can't you admit the truth. Truth is what we see with our own eyes. If the emissions control would be so easy problems then the President and Defense Secretary would not allow National Laboratories and Leading Universities facilities to utilize super-computers to perform computer simulations to tackle this kind of problems. 'WAVE' or other commercial softwares are mole-hills in a mountain and have limited applications. I am repeating again that this is not a child's play anymore. It may be in the past but not anymore.

Re: WAVE Ricardo Software
 

Hi Mohammed,

I am interested in more details on these legal implications nad the example that you cite with the auto companies. I am in Canada and we are less apt to lawsuits but it is clear that there will be liability implications in the future. It is my understanding from several of the code delvelopers that there is lots of "small print" in the code liscence that basically says the code is not suited to do anything and the code developer is not liable for an idiot who uses it without adequate training in both the code mechanics and the general area of fluid mechanics and transport, etc.

Do you have any references (newspaper articles, law articles, etc.) that deal with the cases that you mention!

Thanks for the interesting and timely topic!

Duane

Re: Ricardo & WAVE
 

So what exactly are your National Labs and Superuniversities working on and what are they running on their Supercomputers?

Are they able to do a DNS for a complete engine with all surrounding parts including combustion?

Over the last 10 years there were several european programms funded by the EU and some automotive companies to find out a little bit more about the physics in engines.

Do you really think that a "Leading University" just has to switch on a supercomputer and suddenly becomes lightyears better than all others?

Re: Ricardo & WAVE
 

IC Engine is almost in a mature stage. Only problem is now to find ways to reduce emissions. National Laboratories and your mentioned Superuniversities are putting their heads together to reduce emissions in IC engines, Gas Turbines and other industries.

Accelerated Strategic Computing Initiative (ASCI)

Academic Strategic Alliances Program (ASAP)

For proposal questions contact: Lynn E. Rippe, alliances@llnl.gov

For technical questions contact: Dick Watson, Lawrence Livermore National Laboratory Ann Hayes, Los Alamos National Laboratory Charles Hartwig, Sandia National Laboratory

UCRL-MI-125901 Modified on 9/29/99.

Re: WAVE Ricardo Software
 

Technical Note John,

Star-CD also has unstrucuted FV capabilities!

...............................Duane

Re: WAVE Ricardo Software
 

Usally, I read Detroit Free Press. If you are interested then you can go to the library and find out. You can also go to specially Diesel Engine Companies directories and find out the persons to contact. If you look at Detroit Free Press of yesterday, you can find out about the 1.9 billion dollar lawsuit against GM in California. GM is claiming that the lawyers are after Automotive Engineers. My believe is that lawyers are after anybody where they can find faults.

Re: WAVE Ricardo Software
 

John,

what do you mean by:

"The code should be in perfect condition to solve the user's problem when it arrives at the user's site. Otherwise, it should be returned."

I hope you don't mean that the disk is scratched or the maual has a coffee stain on it? (Pardon my sarcasm) We are not talking about buying a pair of shoes! How can a user anticipate apriori all of the needs for a CFD code and then evaluate the adequacy of a code for these needs at the time it is delivered. The process of CFD code development and CFD use is an iterative and growing one. The most important factor in the CFD industry is the commercial code developer's ABILITY AND WILLINGNESS to meet the customer's needs. That is an ongoing process NOT a package that arrives on the doorstep!

Regards,

Duane Baker

Re: Ricardo & WAVE
 

As a forewarning, I am an employee of Gamma Technologies, which writes and markets GT-Power, a competing engine simulation code to WAVE. I will try not to make this an advertisement.

I feel the need to point out that these codes are made to simulate the airflow and combustion in an engine mostly to simulate the performance of an engine, i.e., power, torque, fuel usage and acoustic characteristics. They can also be used for muffler matching, warm-up studies, performance when attached to specific vehicle, etc. Emission predictions are only part of the package. It is also well known to us and others that there are limitations to the emission predictions right now. KIVA may be a better code to use for this at this point in time.

Above all, I don't think any code can be used to design a product without experimental validation. The purpose of simulations is to reduce the cost and time spent on product development by building a model that can be validated and then optimizing the design on the computer, and then building a final design and verifying the simulations again. This will reduce the number of prototype which need to be built, hence reducing the cost and time spent in development. This is true of FEA, CFD or any specialized code. Simulations are not meant to eliminate the need for experimental testing. Maybe they can be sometime in the future when these codes have been perfected, but they can never eliminate typographical errors, misreading of blueprints, etc.

Re: Ricardo & WAVE
 

KIVA may be a better code to use for this at this point in time. I am impressed that at least somebody is admitting the truth. Yes, I agree with you that we still need to do experimental testing. Thank you T.J. Wanat.

Re: Ricardo & WAVE
 

(1). I think, you are right. (2). Whether we say it explicitly or implicitly, a product has to go through the validation, verification phases before it can be called a product. Otherwise, we can only call it a prototype at best. (3). Whether that product is a hardware product, or a software product, there are always standard procedures required to ensure the integrity of the product. (4). So, I think, the responsibility is on the developer's side to properly validate and verify the product for the intended range of applications. This common sense guideline is applicable to both the performance codes or 3-D CFD codes. (5). Experimental testing is one way to achieve this goal.

Re: WAVE Ricardo Software
 

(1). You have raised the core issue of CFD software. (2). It is a much bigger issue and should be discussed separately. (3). I think, as a product, there is no difference between a pair of shoes , a computer game, or a CFD software. (4). What you mentioned was CFD consulting service.

Re: WAVE Ricardo Software
 

You maybe a nice person but when you are coming to engineering technical issues, there is no compromise. Phillip Colella of Mechanical Engineering, UC Berkeley is working to develop software for IC engine performance in USA. You can also search for IC engine at University of Wisconsin, Madison, Engine Research Center and find out what software they are developing. I am a novice in this field. Getting angry with me will not solve problems. I am also attaching some information about KIVA below (KIVA is used in Sweden for developing Volvo engines.)--

MODELING OF SPRAY FORMATION,

IGNITION AND COMBUSTION IN INTERNAL

COMBUSTION ENGINES

Valerie Golovitchev, Assoc. Professor Niklas Nordin, PhD student

Jerzy Chomiak, Professor

This report presents the results of the third stage of the project with the aim of

developing a research CFD code for numerical simulations of reacting

multi-phase flows in piston engines, including soot and NOx formation. The

main goals of the project have been formulated in our previous annual report

1997.

The KIVA3 and KIVA-3V versions of the KIVA code are used for simulation,

with modified sub-models of fuel atomization, droplet evaporation, turbulence,

ignition, combustion, NOx and soot formation based on the RNG k-e

turbulence model. Such an approach allows for the treatment of

compressibility effects, detailed chemistry and turbulence/chemistry

interaction accounting for the reactant segregation, micro-mixing and sub-grid

scale reaction rates.

The neat dimethyl ether, DME, has been the fuel of choice due to two

reasons: there is substantial interest in the use of DME as a potential Diesel

fuel, the combustion chemistry of DME in air is relatively simple, albeit

almost unknown, and simulation can be done using a detailed chemical

mechanism. In addition to previous model verifications, the spray atomization

and evaporation models were tested once again using the constant volume

vessel experimental data obtained at the University of Hiroshima by Nishida

et al. The accuracy of the models at Diesel-like conditions is evaluated by a

comparison of predicted and experimental data on liquid and vapor phase

penetrations and ignition development. Then, the computational model was

applied to an axisymmetric bowl-in-piston engine geometry with a peak in the

center of the bowl to evaluate the performance of the turbocharged Volvo

AH10A245 DI Diesel engine fueled by DME. The results of numerical

simulations allowed to preliminary answer the question: "Is neat DME really

Diesel fuel of promise?"

The models of fluid dynamics, turbulence, chemical reactions, droplet

evaporation, collision and dispersion and so on, were used to reproduce the

whole picture of turbulent spray combustion. Model validation and

modifications are the subject of current work. As a part of the validation

procedure, the KIVA computer results were compared with those produced

with the help of the commercial AVL FIRE code.As a result of this work, the

FIRE code fuel library has been updated using our recommendations and

software.

Recently, the reduced, but still comprehensive (44 species, 195 reactions

including NOx chemistry), chemical mechanism for a generic aliphatic

hydrocarbon fuel has been developed and applied to n-heptane combustion.

The model has been supplemented by soot formation and oxidation processes.

Brief description of the soot model is given below.

Table 1. Large processes and rate constants of the soot model

No.

Formation subprocess

Reaction rate const.

Ai (mol,cc,s)

Ei (cal/mol)

1.

Fuel (n-Heptane) consumption

Detailed chemistry

2.

Precursor radical formation

k1 = A1 exp(-E1/RT)

7.00*10e11

1.20*10e5 3.

Acetylene formation

Detailed chemistry

4.

Precursor radical oxidation

k3 = A3 exp(-E3/RT)

1.00*10e12

4.00*10e4 5.

Acetylene oxidation

Detailed chemistry

6.

Soot particle inception

k5 = A5 exp(-E5/RT)

1.00*10e10

5.00*10e4 7.

Soot particle growth

k6 = A6 exp(-E6/RT)

4.20*10e4

1.20*10e4 8.

Soot particle oxidation

Nagle and Strickland-Constable

Constants:

kA = AA exp(-EA/RT)

2.00*10e1

3.00*10e4

kB = AB exp(-EB/RT)

4.46*10e-3

1.52*10e4

kT = AT exp(-ET/RT)

1.51*10e5

9.70*10e4

kZ = AZ exp(-EZ/RT)

2.13*10e1

4.10*10e3

Reasonable agreement between computational and experimental data

for DME ignition at high pressures in a constant volume bomb have

been achieved. The conditions of effective performance of DI Diesel

engines fueled with neat DME are formulated.

The general structure of the soot model formation and oxidation

developed looks similar to that developed by Fusco et al. (see

Proceedings of COMODIA 94, Yokohama, Japan, pp. 571-576

(1994)), but this does not belittle its merits because of all model

components are different. The main processes of our model are shown

schematically in Figure 9 and Table 1. The pre-soot chemistry is

represented by the detailed oxidation mechanism that includes

formation of main sooting agent acetylene, C2H2, and some of its

higher derivatives. Such an approach is reasonable for the combustion

of both low and aliphatic hydrocarbons. Soot inception has been

simulated via conversion of soot precursors into incipient soot

particles in the "quasi-equilibrium" processes CH4=2H2 +C(s),

C2H2=H2 +2C(s).

The notation C(s) + H2 can be formally attributed to incipient soot as

the latter contains a significant amount of hydrogen. This is, strictly

speaking, not correct, but has, however, been adopted in the absence

of a more acceptable alternative.

Then, the Nagle-Strickland-Constable model in the form of surface

kinetics relations has been used for oxidation of carbon. It is proven

that the contribution of O2 to the oxidation of soot is minor. It appears,

therefore, that the oxidation of soot occurs by the OH and HO2

radicals, and NO molecules. These processes were accounted for on

the same basis, but with increased "diffusion" efficiencies. Important

steps of CO formation with the heat release effect and consumption of

oxidizing species were also accounted for.

Such a model was implemented into the KIVA-3 code and applied to

the turbocharged Volvo AH10A245 DI Diesel engine fueled by neat

DME. The concentration of soot was found to be noticeable, see

Figure 10. This is no wonder that soot is formed in the case of the

oxygenated fuel: DME represents the partially oxidized fuel rather

than the substance containing not bounded oxygen in its molecule.

Spatial destribution of soot well correlates with the fuel rich, high

temperature (T>1100 K) region.

Future research will focus on detailed comparisons with benchmark

engine data fueled with hydrocarbons.

FIGURE 10. Gas and droplet

temperatures, and concentration

of soot at different crank angles

for the Volvo AH10A245

engine. DME injection starts at

-15 ATDC with a timing of 10

CA.

Re: WAVE Ricardo Software
 

I've heard that they developed a really good CFD IC engine code at UC Santa Barbara. Does anybody know anything about it? Otherwise I agree that there should be no compromise when it comes to technical issues.

Re: WAVE Ricardo Software
 

I don't mind accepting the new technology. If you have more information then please let us know.

Re: WAVE Ricardo Software
 

Why are you quiet now? Give us some information or you are just saying without knowing anything. We all are here to hear from you. Oh, I can't believe I am getting so famous! I am not an automotive engineer but technically (in engineering point of view) knocking out most automotive engineers. Guess how can it be possible!!

Re: Ricardo & WAVE
 

I even heard some companies are trying to use the software "WAVE" to analyze flow simulations and acoustics analysis through mufflers of an automobile. I would not be surprised if the company's sales go down due to not using state of the art softwares. After all, competition in the market is so challanging that nobody can afford to do momopoly business anymore.

Re: Ricardo & WAVE
 

In mufflers, exhaust gases pass through myriad preforated or drill small holes to attenuate sound intensity. As the exhaust gases pass through small holes, sound source is dissipated by friction or interference. Therefore, sound is reduced. Now we can see that these drill holes play vital role in reducing sound. These holes are two dimensional or three dimensional. So how can a software like "WAVE" with one dimensional capabilities handle flow simulations and pressure distributions through perforated holes!

Re: Ricardo & WAVE
 

The flow in a pipe is also 3d and we are still using the "Bernoulli Equation" for a lot of tasks. And this is a 1d description of the flow :))

But if you really want to use "state of the art" physics then you will find that even the "Navier-Stokes-Equation" contains a lot of simplifications ......

And please forget all you've learned about physics at school, because the simplifications there are horrible.

Re: Ricardo & WAVE
 

For simplicity, "Bernoulli's Equation" is used for simple incompressible pipe flows, channel flows etc. But if you would like to simulate flows and pressure distributions through perforated pipe then your mentioned "Bernoulli's Equation" is not enough. You need to use 2D or 3D simulations.

Re: Ricardo & WAVE
 

I'm surprised this thread has been revived. Mr. Islam, have you seen any comparisons of the acoustic predictions of an engine simulation code versus experimental data? I have and they're quite good. The computational expense of building a model of a muffler in 3-D (there are very few mufflers which can be represented in 2-D) and running it seems excessive, like driving a Formula 1 race car down the street to pick up a gallon of milk. Sure it's state of the art, but the cost is impractical. I could build a muffler model and calculate a transmission loss in less than an afternoon using GT-Power. How long will it take to build and run a 3-D model using the software of your choice? Does it include subroutines to calculate transmission loss or do you have to write a subroutine to do that? What type of boundary condition should you use? Industry is not looking for state of the art unless it can also be productive. The additional 1-2% accuracy gained is not worth the large increase in time and expense. In fact, engine simulation codes can generate a sound file of an accelerating vehicle including the gear shifts and it sounds damn good!

Actually the only noise that can't be modeled in an engine code is flow noise generated by turbulence. But in order for a 3-D code to simulate that it would have to include all of the space between the exhaust and the microphone, which could easily turn into several million grid points.

If your specialty were acoustics I would take you more seriously, but I'd bet you have never even tried to model a muffler in either 1-D or 3-D. And just so you know, perforations are easily handled by these codes. The people who wrote them were well aware of their presence in mufflers.

Re: Ricardo & WAVE
 

"I'd bet you have never even tried to model a muffler in 1-D."

Answer

Let me explain to you more clearly why 1-D model will not give better results. In mufflers, there are perforated pipes. Let us consider that we are doing simulations in x-directions. But the exhaust gases passes through the perforated holes in another direction. So there is no way you can get better results using 1-D model. I think you have a big problem with your conception.

Re: Ricardo & WAVE
 

You are right 1-D will not give you better results than 2-D. But it will give you acceptable results at a much lower cost than a 2 or 3-D will. A right angled branch or junction with multiple pipes is a basic building block of any 1-D model. Maybe 1-D is a limiting term. A network of pipes can be assembled, so maybe "network solution" is better. No engine company would license software that can't model branching. If you don't believe that is can be done, check out SAE technical paper 910072. Don't knock it until you try it.

Re: Ricardo & WAVE
 

..."Actually the only noise that can't be modeled in an engine code is flow noise generated by turbulence. But in order for a 3-D code to simulate that it would have to"...

Can someone explain how to simulate turbulence flow noise. Is it involved turbulence energy level?