Hello, when we study laminar mixed convection water or nanofluids in circular duct, we use boussinesq hypothesis and define density and thermal expanssion. Also, inlet temperature, inlet velocity, outlet pressure and heat flux at the wall boundary layer, So, How to set operaing condition in this case( operating density and temperature)? what is the range of temperature difference at any cross section the boussinesq hypothesis is valid? can we using incompressible ideal gas in liquid when use mixed convection?
I did same problem but just changed the Rayleigh number to turbulent, used k-e turbulent model, the results are not convergeing and also the thermal distribution is totally different Can you suggest how to approach the problem when flow is Turbulent ?
Why doesn't this simulation account for radiation? It should be fairly significant. Also, how would one go about doing this? I have seen multiple videos about radiation between walls but I can't find any information about how to simulate radiation into the open atmosphere.
![[CFD] The Boussinesq Approximation for Bouyancy Driven (Natural Convection) Flow](/img/n.gif)
Hi, how did you calculate operating density? I get different results using various operating densities.
Hello, when we study laminar mixed convection water or nanofluids in circular duct, we use boussinesq hypothesis and define density and thermal expanssion. Also, inlet temperature, inlet velocity, outlet pressure and heat flux at the wall boundary layer, So, How to set operaing condition in this case( operating density and temperature)?
what is the range of temperature difference at any cross section the boussinesq hypothesis is valid?
can we using incompressible ideal gas in liquid when use mixed convection?
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I did same problem but just changed the Rayleigh number to turbulent, used k-e turbulent model, the results are not convergeing and also the thermal distribution is totally different
Can you suggest how to approach the problem when flow is Turbulent ?
Thanks for watching! Please post your query on the Ansys Learning Forum for a detailed answer from the wider Ansys Community: ansys.com/forum.
Hi, can i do this simulation with constant heat flux in the sink surface ?
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Hello friend. How can I do free convection with constant heatflux
Why doesn't this simulation account for radiation? It should be fairly significant. Also, how would one go about doing this? I have seen multiple videos about radiation between walls but I can't find any information about how to simulate radiation into the open atmosphere.
Hello! Please visit our Ansys Learning Forum for support at www.ansys.com/forum.