Fluids

What boundary condition should I apply for solving solar chimney problem

• shreebhagyesh
Subscriber

I am doing cfd analysis of a solar chimney power plant. At roof inlet, the air is at ambient condition, but when it passes through the turbine at the center, the velocity of air is 15 m/s. What should I do, so that i can get proper results. Please someone help me out in.

• vinayak chauhan
Subscriber

hi,

You can make a model such that,

it has a velocity-inlet(15 m/s) with initial temperature(calculated analytically)

outlet boundary condition as pressure outlet=1atm alongwith ambient temperature(known)

It would be easier if you first perform a 2D analysis.

• shreebhagyesh
Subscriber

Thank you so much sir for replying me. Actually at inlet there are two stages. First the ambient air at atmospheric pressure will come in the duct. At second stage, a turbine is there which causes 15m/s velocity. How to achieve that condition? Can you help me out please.

• vinayak chauhan
Subscriber

Hi,

You can make an enclosure(geometry) and place your turbine in it according to your design ,then create one side of enclosure as inlet and use your boundary condition , another end as your outlet boundary condition . You can also give velocity to your turbine by creating a suface and giving that surface your calculated velocity.

hope that works for you.

• vinayak chauhan
Subscriber

hi,

according to your design i think you have placed your turbine in the vertical section, so u can create an internal surface in that position and give that surface 15m/s velocity, rest boundary conditions you can give at the inlet portion and outlet at the top.

• shreebhagyesh
Subscriber

Hello Sir

I have applied the same thing and I got the desired results. Thank you so much sir for you help.

• Rob
Ansys Employee

Thanks Vinayak.

Just to add, you may need to use pressure boundaries carefully along with temperature varying density. The above solution forces the flow, are you trying to find the velocity or.....?