Convection+conduction 2D
 

Hi, I have code about convection at vertical plate. I program it analytical with application boundary layer.

1, how i can add conduction process which will work together with convection in this process? I know temperature at some moment which is calculate with convection but i would like to get temperature which would be result from convection+conduction. I dont know which conditions are there.

2, Or how i could use time variable in my code? I know temperature in some space, but at next moment which temperature is for me boundary layer for next calculation?

Thanks for any advice.

Jozef

Re: Convection+conduction 2D
 

Still one question :)

Which process is occur for example in tank, or boiler inside? I think that convection, conduction. Radiation occur only outside maybe. Thanks

Re: Convection+conduction 2D
 

If you are talking about transient problem, you should have youe energy balance including change over time + convection energy = conduction energy At the boundary you should balance conductio ( Fourier law) with convection (Newtons law of cooling). You can have a radial resistance balance from the fluid temperature inside the boiler to the inner wall of the boiler, to the flue gases (for example if water tube boiler), to the external wall, to the surrounding.

Re: Convection+conduction 2D
 

Hi, I`ve tried to give the answer for your question in my book. Best Regards, Yuri

http://www.amazon.com/Theory-Periodi.../dp/3540707239

The main point of the book is the simplifying description of the interaction between solid body (wall) and fluid as a boundary value problem of the heat conduction equation for the solid body. At the body surface the true heat transfer coefficient is composed of two parts: the true mean value resulting from the solution to the steady state heat transfer problem, and a periodically variable part, the periodic time and length of which describe the oscillatory hydrodynamic effects. In this way, the conjugate heat transfer problem is reduced to the solution of the heat conduction equation, yielding the temperature field in the solid body and consequently the conventional mean "experimental" heat transfer coefficient. The key parameter of the method is the coupling factor, defined as the ratio of the experimental and the true mean heat transfer coefficient. This parameter represents a new terminology in heat transfer theory. The derived method leads to two important conclusions concerning the wall effect, which are described by the value of the coupling factor. For any type of body-fluid interaction the coupling factor always falls below one. This is proven by an exemplary theorem which represents the fundamental qualitative result of the new method. The coupling factor is a function of the coupling parameters Biot number, Fourier number, dimensionless geometry and oscillation amplitude parameters. The physical foundation and development of the analytical calculation algorithm for the multi-parametric relationship represents the quantitative application oriented result of the method. The solutions found with this algorithm are presented to engineers and researchers in form of tables and diagrams for direct application.

Re: Convection+conduction 2D
 

Wow!

That's an expensive book.

Did you investigate 'self publishing'? That's been touted as a way to avoid high publishing costs, thus selling to a larger market of folks who can afford a lower-priced volume.