DDPM, Accumulation of Particles in Elbow Bend, ANSYS Fluent Training
Accumulation of Particles Inside An Elbow Bend using DDPM is simulated by ANSYS Fluent software.
This product includes a Mesh file and a comprehensive Training Movie.
There are some free products to check our service quality.
To order your ANSYS Fluent project (CFD simulation and training), contact our experts via [email protected], online support, or WhatsApp.
Project Description (DDPM)
While the DPM strategy for CFD solutions proved to be an excellent method to calculate flow particle-flow studies, this approach cannot provide reliable answers for dense particle simulations.
To remove this issue, the DDPM (Dense-Discrete-Phase-Method) is mostly employed in CFD projects. For instance, in the current project, we have simulated a simple elbow bend. However, the fast injection would result in a dense accumulation of particles. Therefore, a dense DDPM model is employed. Our computational domain comprises a 25 [mm] annulus of the air and particle mass flow of 4.34×10-7 [kg/s]. The diameter of particles considered 10.06×10-12 [m] with a velocity magnitude of 0.09625 [m/s]. Both phases were considered unsteady, and the injection time for the particle was considered equal at each flow time-step of 0.005 [s].
To study the current problem, one must solve the flow equations in the differential form. Also, we assume the incompressible and turbulent condition inside the elbow geometry since the particle-flow interactions are more likely to create a turbulent condition flow. Also, we have employed a Realizable k-epsilon model with Menter-Lechner wall-function to account for our boundary layer.
Geometry and Mesh
As a numerical study, the initial step towards the modeling is the production of the CAD geometry. We consider the blue face as the inlet of the domain while the red face as the outlet. For the current problem, we generate a mesh count of 150,624 elements to represent half of the domain and used symmetry at the mid surface of the domain. Regarding the quality of the mesh, the maximum skewness of 0.05 is low due to being a structured mesh. Finally, we performed the meshing operation via ANSYS-Meshing software.
DDPM Simulation Settings
When we import the mesh into the ANSYS-FLUENT solver, the calculation procedure could be started. The details of the solution setup are as follows:
|Gravity:||g = -9.81 Y-direction|
|Zone:||fluid zone: air-particles|
|Multiphase setup:||Eulerian: DDPM: Implicit
Number of discrete phases: 1
Primary phase: air
Secondary phase: Ion
Forces: Drag/Lift/Wall Lubrication/Turbulent Dispersion/Turbulent Interaction/Surface Tension = DPM averaged
|DPM setup:||DPM Iteration Interval: 200
Unsteady Particle Tracking
Track with Fluid Flow Time-step
Max Number of steps: 10,000
Step length factor: 12
Linearize source term and Node-based averaging On
|Boundary conditions:||Inlet: velocity inlet: 4.37×10-7 kg/s, 300K, escape
Outlet: pressure outlet, zero gauge pressure, escape
Inner wall: No-slip, reflect, 310K, reflect
Outer wall: No-slip, reflect, 310K, reflect
Mid wall: Symmetry
|Injection setup:||Injector: Inlet surface
Velocity: 0.09625 m/s (face normal direction)
Total flow rate: 4.37×10-7 kg/s
Temperature: 300 K
Diameter: 10.06×10-7 m
|Operating Condition:||Reference Pressure Point: 101325 Pa|
Time-step: 0.005, Number of Iterations = 2000
Number of time-steps: 2000
|Initialization:||Standard > from inlet|
|Fluid:||Air – constant properties
Particle: 2700 kg/m3 ; 14310 j/kg.K
Accumulation Results and Discussions
In the current study, we have followed the convergence up to a tight residual value of 10-10. By adding more particles to the domain, the necessity to improve the convergence became more critical due to the higher impact of the source term. Also, the mass average of the source term in y-direction was monitored during the solution to ensure that each time-step satisfied the required accuracy.
Afterward, the pressure and velocity field results are depicted for both particles and the air-fluid flow below the figures.
As it could be observed, the air velocity s increased as the flow reaches the bend section. Also, the flow temperature close to the hot wall, which is the inner wall, is higher than the other side of the pipe. Furthermore, the hot temperature diffused among fluid flow and particles over time. Interestingly, the same results were observed from the DPM particle calculations that both velocity and pressure were higher at the exact locations.
Additionally, the streamlines also imply that several vorticities were formed close to the bend location that is usually interesting for erosion simulations.
A Mesh file and a comprehensive Training Movie present how to solve the problem and extract all desired results.