In fluid dynamics, objects of interest are generally moving through a quiescent fluid. For example, a car driving on the road with a constant velocity is moving through the still air. To analyze the airflow around the car, we generally recast the problem in the reference frame of the moving object. We assume that the car is stationary and the air is approaching it at a constant velocity. Another approach to solving this problem is to assume that the quiescent air is stationary and the car is moving through this stationary air with a constant velocity. The moving reference frame (MRF) modeling methodology can be applied to simulate the car’s motion in the steady-state approach.
In the previous simulation example, we used Ansys Fluent to solve for the laminar boundary layer velocity profile on a stationary flat plate and compared the obtained solution with the Blasius solution. We will now use the MRF approach to solve for the same velocity profile on the flat plate. Here, the flat plate is assumed to be in motion with respect to the stationary surrounding fluid. As part of the homework, you will compare predicted velocity profiles and skin friction distribution with those computed in the stationary flat plate example to confirm that both approaches yield identical results once they are presented in the same frame of reference.
The main objective of this example is to obtain the laminar boundary layer velocity profile on a moving flat plate. Here, the plate is moving at a constant velocity of 1 m/s. The quiescent fluid surrounding the flat plate is air. Through this example, you will also learn how to set up the MRF model in Ansys Fluent. The solution should match the analytical results from the Blasius boundary layer solution for laminar flow over the flat plate when presented in the same frame of reference.
Download the Mesh file needed for setting up the simulation and the associated Case & Data files here. Follow the instructions below to set up this simulation in Ansys Fluent starting with the Mesh file. In case you face any issues setting up or running the simulation, please refer to the corresponding initial and final Case and Data files.
Let us now analyze the simulation results and understand the physics of the flow due to a moving flat plate.