Simulation flow through Propeller by SRFSimpleFoam

 Register Blogs Members List Search Today's Posts Mark Forums Read

 September 7, 2013, 07:28 #2 Senior Member   sivakumar selvaraju Join Date: Mar 2009 Location: Cape Town - South Africa Posts: 186 Rep Power: 10 Hi, Actually your questions are not clear, however I will try my best. Have a look of the following thread for calculating initial value for k and epsilon. http://www.cfd-online.com/Forums/ope...urbulence.html To get the forces and torque, just copy and paste the following function underneath your controlDict file. functions ( forces { type forces; functionObjectLibs ("libforces.so"); outputControl timeStep; outputInterval 10; patches (fan); // pname p; // Uname U; rhoName rhoInf; log true; rhoInf 1.20; CofR (0 0 0); } ) Thanks, Sivakumar Last edited by sivakumar; September 9, 2013 at 03:30.

 September 8, 2013, 11:39 #3 New Member   DANG QUOC BAO Join Date: Apr 2013 Posts: 12 Rep Power: 6 Dear Sivakumar I am grateful to you for your reply. I will describe my problem. I have propeller with diameter 9 inchs and picth 6 inch (Master propeller 9x6 for UAV). I had done experiment in windtunnel with this propeller and determined their thrust and torque. Now, my problem is how determine thrust and torque of propeller by numerrical method using OpenFOAM. I have 3D model of propeller and generated mesh. Parameter of propeller: inlet velocity (speed flight): 10 - 15 m/s; RPM of Propeller 4000 - 8000 RPM; chord of propeller 0.75R = 17 mm. I used tool estimate yplus of CFD online and calculate yplus. My mesh model has the first node from surface blade yplus = 20. For simulation flow through this propeller, i used solver SRFSimpleFoam version 2.1.0 and turbulence model Komega SST (flow steady and incompressible). I set value of boundary conditions k, omega, nut, p, Urel as in last post (please see last post). I calculate 1000 time but I have result different pressure very large and force very large (> 10000 N). I think wrong because force and pressyre very large. Would you mind help me solver this proplem? 1) With my problem, I used solver SRFSimpleFoam is right or wrong? Which is solver of OpenFoam i can calculate thrust and torque of propeller (steady and incompressible) ? If i use another solver of openfoam, do i change mesh mode of propeller? 2) How to calculate value of boundary condition of Problem? which is turbulence model i can choose for solver this problem? 3) Do you have tutorials OpenFoam relation simulation flow through propeller? please share me...? Please help me... Thank you very much. Baoaero.

 September 9, 2013, 04:17 #4 Senior Member   sivakumar selvaraju Join Date: Mar 2009 Location: Cape Town - South Africa Posts: 186 Rep Power: 10 Hi, There are two options in OF to solve the problem, one is SRF and another one is MRF. Getting torque and force from MRFSimpleFoam is very simple, just you need to copy and paste the function in your controlDict file. (the function is from the forum only), but I am not sure how to get torque and force from SRF solver, I dont think the function will work with SRF solver. I can help you for MRFSimpleFoam solver, if you like give me your email id, I will send you the tutorial. Regarding the turbulence model, its up to your need. If you are interested to calculate stall, the low-Re model is appropriate, then your Y+ value should be 1, otherwise you can use hi-Re model, which the Y+ range should be 30-300. Thanks, Sivakumar

 September 9, 2013, 04:40 #5 New Member   DANG QUOC BAO Join Date: Apr 2013 Posts: 12 Rep Power: 6 Dear Sivakumar Thank you for your advances. My email; baodangacv@yahoo.com or quocbao@vietnamairport.vn. I will use MRFSimplefoam for simulations propeller. I need calculate force and torque of propeller. How will i refine mesh model of propeller for using solver MRFSimplefoam?. Please help me...Thanks you very much Baoaero.

 September 9, 2013, 21:13 #6 New Member   DANG QUOC BAO Join Date: Apr 2013 Posts: 12 Rep Power: 6 Dear Sivakumar I received the file fan tutorial from you. Thank you for your sharing. Can you guide me for generating Mesh model of Propeller when i use MRFSimplefoam. How many calculated domain of Mesh model? Please help me... Thank you very much. Baoaero

 September 10, 2013, 03:33 #7 Senior Member   sivakumar selvaraju Join Date: Mar 2009 Location: Cape Town - South Africa Posts: 186 Rep Power: 10 Hi, Have you gone through the tutorial? I have explained everything in that. The problem is I dont know how you want to model your propeller, in my case I am using 3 volumes. Inlet volume, fan volume , and outlet volume. go through the tutorial once again then you will come to know. Thanks, Sivakumar

 October 1, 2013, 10:44 #8 New Member   Join Date: Sep 2013 Posts: 12 Rep Power: 5 hi, i hope i can use this thread for my question. i want to simulate a kind of propeller, too. i desgined the propeller in solidworks and put it with snappyhexmesh in a mesh created up by blockmesh. the propeller should rotate in still water. so there is no inflow. my question ist, who to set the boundery settings? i user to solve the problem the SRFSimpleFOAM solver. i set the inlet: Code: ``` inlet { type SRFVelocity; inletValue uniform (0 0 0); relative yes; value uniform (0 0 0);``` and the outlet as type "slip". the shape of the propeller is: Code: ``` type fixedValue; value uniform (0 0 0);``` are these bounderysettings ok or are they false?

 October 2, 2013, 02:51 #9 New Member   Thomas Reviol Join Date: Jul 2011 Location: Germany, Kaiserslautern Posts: 27 Rep Power: 8 Hi, "slip" for free surface and "fixedValue" for propeller shape are ok. And I never set an inlet condition, too. Are the boundaries of your fluid domain open for in- and outflow? In this case you could use an "inletOutlet" condition. When your fluid domain is a vessel from process industry, you need neither an inlet nor an outlet. In this case all your boundaries are walls. I hope I understood your question correctly and I could help. Regards Thomas

 October 2, 2013, 02:57 #10 New Member   Join Date: Sep 2013 Posts: 12 Rep Power: 5 hi Thomas, thank you for your answer. the bounderies are patches, except the propeller-boundery, which is a wall. what do you mean with "open for in- and outlet"? with fluid domain, you mean the initial conditions? the propeller should be in a "open ocean", no borders etc. in german: Hallo Thomas, danke für deine Antwort. Eigentlich hab ich nur patches, außer dem Propeller, welche eine wall ist. Was meinst du mit "open for in- and outlet" und "fluid domain"? der propeller soll im offenen wasser sein, also keine grenzen oder hindernisse.

June 24, 2016, 06:53
#11
Member

alex
Join Date: Feb 2016
Location: chennai
Posts: 48
Rep Power: 3
Quote:
 Originally Posted by sivakumar Hi, Have you gone through the tutorial? I have explained everything in that. The problem is I dont know how you want to model your propeller, in my case I am using 3 volumes. Inlet volume, fan volume , and outlet volume. go through the tutorial once again then you will come to know. Thanks, Sivakumar
can You send the tutorial to my email ID ?
my mail Id is velan45@gmail.com

October 24, 2016, 03:11
#12
New Member

Aldias Bahatmaka,ST
Join Date: Aug 2015
Location: Busan, South Korea
Posts: 28
Rep Power: 3
Quote:
 Originally Posted by sivakumar Hi, There are two options in OF to solve the problem, one is SRF and another one is MRF. Getting torque and force from MRFSimpleFoam is very simple, just you need to copy and paste the function in your controlDict file. (the function is from the forum only), but I am not sure how to get torque and force from SRF solver, I dont think the function will work with SRF solver. I can help you for MRFSimpleFoam solver, if you like give me your email id, I will send you the tutorial. Regarding the turbulence model, its up to your need. If you are interested to calculate stall, the low-Re model is appropriate, then your Y+ value should be 1, otherwise you can use hi-Re model, which the Y+ range should be 30-300. Thanks, Sivakumar
Hello Mr.Sivakumar,

can you share your tutorial to email ? i need some help from you too,
my email is bahatmaka.aldias@gmail.com
thanks so much for your kindness.

 October 24, 2016, 05:23 #13 Member   alex Join Date: Feb 2016 Location: chennai Posts: 48 Rep Power: 3

 November 21, 2016, 08:07 #14 New Member   hesam Join Date: Apr 2014 Posts: 4 Rep Power: 5 Hi I want an article or any documents about propeller with all details about prop geometry and fluid flow to verify my case simulation. ِDose anybody Case? can you share your article or document to my email ? i need some help. my email is hesam.gazor@gmail.com thanks so much for your kindness.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post castaway FloEFD, FloWorks & FloTHERM 3 September 11, 2012 12:44 SimonH. OpenFOAM 0 October 27, 2009 05:39 Teng_YJ FLUENT 2 February 16, 2009 20:37 Kes FLUENT 2 May 27, 2008 04:48 KK CFX 1 February 25, 2008 17:29