'Flow analysis of a Mixing-Diffuser' simulation project by Ali_Arafat


I created a new simulation project called 'Flow analysis of a Mixing-Diffuser':

This project simulates flow in a mixing-diffuser for juice flushing.

More of my public projects can be found here.


The project simulates laminar flow inside of a Mixing-Diffuser via Transient Scalar transport analysis. The source geometry inculdes a sample Mixing-Diffuser model with 3 inlet sections and 1 outlet. The pipes have internal diameter of 0.08 m and overall dimensions as shown in the figure below.

The domain was meshed using the ‘Snappy-Hex-Mesh’ on the SimScale platform. The resulting mesh consists of approximately 0.45 million cells and is shown in the figure below.


An inlet velocity of 0.04 m/s was taken for all inlets with a reference pressure of value 0 at the outlet. Scalar quantity with value 0 enters via Inlet-1 which is switched on at time = 0 and remains at ON state. While scalar quantity with value 1 enters via Inlet-2 and Inlet-3 which are switched ON and OFF with intervals. The timings for all three Inlets are detailed in the figure below. The total Simulated time was 270 sec with 60 sec of ON state for each Inlet-2 and Inlet-3.

Auto-Time stepping with maximum Courant number = 0.9 was used with Euler implicit time stepping scheme. The job was run on 4 compute cores and took around 22.5 hours. The simulation shows the time dependent mixing and flushing in the Mixing-Diffuser. The results below (processed on ParaView) provide insight as to how the mixing and flushing take place. The figures show the velocity, scalar mixing distribution, and pressure at different times.

The figures below show the velocity field.


Shown below is the scalar distribution.


Shown below is the pressure distribution.


How did you create the streamlines?