Ansys Learning Forum › Forums › Discuss Simulation › Fluids › Discrete phase model (DPM) – Injection speed (m/s) › Reply To: Discrete phase model (DPM) – Injection speed (m/s)
October 26, 2021 at 10:35 pm
ai0013
Subscriber
Yes, just to add a bit more on the # particles / sec:
From the injection panel I see you have a surface injection. Fluent injects 1 parcel per time-step per cell face. So from what I remember, it'd be as follows:
Let's say your surface is composed of 500 cell faces, and that you have 10 diameters in the RR distribution. Imagine your particle injection time-step is 1ms.
Then # particles / sec = 500 * 10 / 0.001 s = 5e6 [s^-1]
Particle mass = pi / 6 * rho_p *d_p^3 [kg]
So based on m_dot [kg/s] , different d_p (based on RR distribution) will be injected to satisfy the mass flow rate. You see you still need to provide particle velocity [m/s] ? That's why you need it as independent input.
You can post your doubts here (As the Forum is public, everybody can benefit )
From the injection panel I see you have a surface injection. Fluent injects 1 parcel per time-step per cell face. So from what I remember, it'd be as follows:
Let's say your surface is composed of 500 cell faces, and that you have 10 diameters in the RR distribution. Imagine your particle injection time-step is 1ms.
Then # particles / sec = 500 * 10 / 0.001 s = 5e6 [s^-1]
Particle mass = pi / 6 * rho_p *d_p^3 [kg]
So based on m_dot [kg/s] , different d_p (based on RR distribution) will be injected to satisfy the mass flow rate. You see you still need to provide particle velocity [m/s] ? That's why you need it as independent input.
You can post your doubts here (As the Forum is public, everybody can benefit )