Determining Collection Efficiency When Using Lagrangian Multi-phase

ptemp · October 15, 2017, 21:58

Hello all,

I am currently simulating water droplet impingement onto a wing. I am interested in determining the collection efficiency of the wing in order to compare with experimental data. My main question is: is there a direct way of determining collection efficiency that is built into STAR?

If not, is there a way to write a field function that references values from the previous time step? I know there are a few ways of calculating collection efficiency. Specifically $\beta$ = ( $\rho$ * dh/dt)/(LWC * V_inf)

-- where $\beta$ is the collection efficiency, $\rho$ is the film density, dh/dt is the increase in fluid film thickness over time, LWC is the liquid water content, and V_inf is the free stream velocity.

If I am able to reference the previous time step values, I can just create a scene of a field function using (Film_Thickness_t-step2 - Film_Thickness_t-step1) = dh/dt.

I would appreciate any input/suggestions you all may have. Thank you!

ilotam · March 12, 2019, 19:00

Hi,

Did you solve this problem?

I have a similar problem for the steady flow simulation with Lagrangian Multiphase. Can not find any field functions that could satisfy the collection efficiency calculation.

October 15, 2017, 21:58	Determining Collection Efficiency When Using Lagrangian Multi-phase	#1
ptemp New Member Paul Join Date: Feb 2017 Posts: 13 Rep Power: 9	Hello all, I am currently simulating water droplet impingement onto a wing. I am interested in determining the collection efficiency of the wing in order to compare with experimental data. My main question is: is there a direct way of determining collection efficiency that is built into STAR? If not, is there a way to write a field function that references values from the previous time step? I know there are a few ways of calculating collection efficiency. Specifically $\beta$ = ( $\rho$ * dh/dt)/(LWC * V_inf) -- where $\beta$ is the collection efficiency, $\rho$ is the film density, dh/dt is the increase in fluid film thickness over time, LWC is the liquid water content, and V_inf is the free stream velocity. If I am able to reference the previous time step values, I can just create a scene of a field function using (Film_Thickness_t-step2 - Film_Thickness_t-step1) = dh/dt. I would appreciate any input/suggestions you all may have. Thank you!

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March 12, 2019, 19:00		#2
ilotam New Member Ilia Art Join Date: Jan 2019 Posts: 2 Rep Power: 0	Hi, Did you solve this problem? I have a similar problem for the steady flow simulation with Lagrangian Multiphase. Can not find any field functions that could satisfy the collection efficiency calculation.