[luca007]

hello please what's the difference between standard calculation and hybrid calculation

[LuckyTran]

I think you are referring to initialization.

Standard initialization allows you specify all the variables directly as initial guesses. Fluent is setup to allow you to easily specify the initial x-velocity, y-velocity, z-velocity, temperature, pressure, etc. all as constant fields over the whole domain. To specify non-constant fields requires some more work, but you can imagine specifying an arbitrary spatial distribution of all variables, everywhere as an initial guess.

Hybrid initialization is a bit more complex. It uses the boundary conditions and then solves an Euler problem. It uses the solution to this Euler problem as the initial guess.

In standard initialization you must provide the initial guess. In hybrid, Fluent guesses them for you. One is not better than the other and your mileage may vary.

[diamondx]

To add to what luckytran said. Hybrid initialization iterate an initial solution using a very coarse version of your mesh.

[Abhii9]

I am giving convection boundary conditions--in which I gave "free stream temp" 273k but in solution it started with 300k why it is so??
Help me..

[Dejavu0206]

This is because (1) your probelme probably initialized at 300K- check your soultion initialization. or (2) there was back flow at the initial time and your backflow temperature is set at 300K.-change your back flow temperature or remesh to prevent backflow.

[Dejavu0206]

Originally Posted by Abhii9

I am giving convection boundary conditions--in which I gave "free stream temp" 273k but in solution it started with 300k why it is so??
Help me..

This is because (1) your probelme probably initialized at 300K- check your soultion initialization. or (2) there was back flow at the initial time and your backflow temperature is set at 300K.-change your back flow temperature or remesh to prevent backflow