[CellZone]

Hi everybody,

simple question:

If I am doing a CFD simulation of a simple aircraft model which sees a flow velocity of let's say mach=1.5.

According to boundary layer theory, the velocity on the walls is be zero. This means, right at the wall the stagnation (total) temperature is equal to the static temperature. So in theory, if I have an adiabatic wall, the whole aircraft should have the same temperature?

When I display this in CFD and choose static temperature for post processing on the walls of the aircraft - the temperature on the walls are varying. Is this coming from the fact that in FV the temperatures are stored in the middle of a volume cell (more or less the static temperature is here a bit lower, since velocity is not zero) and then in post processing it is interpolated down to the adiabatic walls?

Thank you for your opinion

CellZone

[LuckyTran]

If you correctly plot the adiabatic wall temperature, then what you see is the recovery temperature and not the total temperature because the flow stagnates via a real process and not isentropically.

But you need to clarify exactly what "display this in CFD means." Different software do different things. If you choose static temperature and plot on a surface, lots of different things can happen depending on what software you are using. Some plot directly the static temperature of the wall adjacent cells without any extrapolation. Software often have a different variable altogether for storing the wall surface temperatures.


Not all CFD are the same.

[FMDenaro]

We can state the relation T0=constant also in case of non-isoentropic process, for example across a shock wave. But we cannot use the isoentropic relation.