Flow measurement around intake valve pressure condition problem

January 18, 2006, 08:41

hello i'm federico, and i'm new here.
i'm simulating the flow around an intake valve of a four stroke engine, but i've some problems with the pressure; the whole cylinder is 400 mm long and the intake valve is 28 mm wide.
1) inlet condition: given velocity, zero grad p, outlet: given p, zero grad velocity; i made 0.1 s simulation but pressure waves are fluctuating a lot. shall i still make it run for 0.2-0.3 s?
2) inlet condition: given velocity, zero grad p, outlet: pressure transmissive with pinf 89000, value 95150 (ambient p), linf 1000, then 10000, then 100000; in both 3 cases i reached fast convergence, but the pressure went to 97000 kpa! shall i lower pinf to 65000 kpa or so on and change linf?
which of the 2 cases do you think suits better for my simulation
thanks
federico

January 20, 2006, 13:06

it's always me..
for this simulation i'm working with sonicTurbFoam, in a static case, with a 67000 cells of 2 mm exaedrical..

January 18, 2006, 08:41	hello i'm federico, and i'm ne	#1
fedegavo Guest Posts: n/a	hello i'm federico, and i'm new here. i'm simulating the flow around an intake valve of a four stroke engine, but i've some problems with the pressure; the whole cylinder is 400 mm long and the intake valve is 28 mm wide. 1) inlet condition: given velocity, zero grad p, outlet: given p, zero grad velocity; i made 0.1 s simulation but pressure waves are fluctuating a lot. shall i still make it run for 0.2-0.3 s? 2) inlet condition: given velocity, zero grad p, outlet: pressure transmissive with pinf 89000, value 95150 (ambient p), linf 1000, then 10000, then 100000; in both 3 cases i reached fast convergence, but the pressure went to 97000 kpa! shall i lower pinf to 65000 kpa or so on and change linf? which of the 2 cases do you think suits better for my simulation thanks federico

January 20, 2006, 13:06	it's always me.. for this sim	#2
fedegavo Guest Posts: n/a	it's always me.. for this simulation i'm working with sonicTurbFoam, in a static case, with a 67000 cells of 2 mm exaedrical..

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