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air flow through nozzle like structure
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Actually I am simulating the air flow from a nozzle like structure and I get these results. (shown in screen shot)
the velocity at the end point is nearly 1k kmph if the velocity of air at the inlet is 4 kmph. Is there any method to reduce this velocity. |
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Another way is to have a powerful energy dissipation inside the nozzle (something like a very dissipating porous media = very "dense" filter. Porous media is very quick to model in almost all CFD commercial code). However let me tell you, that if the intake velocity is just 4 km/h and the outlet is 1000 km/h (if I undrstood well) there is for sure some convergence problem, if you are working at ambient pressure (may I know the inlet/outlet absolute pressure?) Check the mass continuity at inlet/outlet and you will "debug" your solution. The inlet mass flow rate (in kg/h) should be the same as the outlet mass. Regards |
Absolute Pressure at both the ends (inlet/outlet) is same as that of atmospheric pressure (i.e. 1 atm).
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If we want to have a movement of the fluid (air) from inlet to outlet we need to establish a pressure difference between inlet and outlet, or the fluid doesn't move. My suggestion is to use a much more robust strategy to solve the problem: 1)INLET: impose just mass flow rate (starting with a very low mass flow rate) 2)OUTLET: impose the pressure (in this case 1 atm) 3)Check carefully the results and determine the average inlet pressure. 4)Check if the outlet mass flow rate is the same (within 1% of the value) of those imposed at inlet. 5)Eventually you will use this pressure value in a final (much refined) simulation. Regards |
Ok, I m gonna try it.
Thanks |
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