Lid-driven cavity- Practical importance

Lid-driven cavity is defined as one of the solid walls on cuboid/cube/square moves tangentially to itself. It is a standard problem studied for understanding tangential motion of a boundary wall in a confined volume with incompressible flow and validation of Computational Fluid Dynamics (CFD) codes. 

Problem gained popularity due to its simple geometry, compact domain size and majorly it can be analyzed for wide range of Reynolds number. Though geometry looks simple, flow occurred inside the cavity involves many complexities such as turbulence, re-circulation, fluid trap in re-circulation zones, separation of flow, attachment with both moving and stationary boundary and other flow phenomena. Hence, understanding these complexities makes a good study.

Application

The study of lid-driven cavity gains importance in fluid research because of its application in transport processes in lakes, short-dwell coating, continuous drying and flow in gate slots of water-reservoir dam-gates. 

Simulation

Problem was defined to understand the flow in a cavity as shown below in schematic. Modeled and simulated using commercial CFD software. Numerical solution for a 2D incompressible steady flow equation obtained choosing SIMPLE algorithm to decouple velocity and pressure. The results obtained from the simulation is as shown in Fig (a), (b) & (c) highlighting primary and secondary re-circulation zones (vortex) in vector and stream function plots.

Schematic

Fig (a) Velocity vector plot and Fig (b), (c) Stream function plot

Experimental demonstration on lid-driven cavity can be seen in videos below.

     

Experimental videos from YouTube: Lid-driven cavity flow

Conclusion

Lid- driven cavity is a very conventional problem and served as benchmark problem in validation of techniques and methods for numerical accuracy. Over the period this problem is studied by many researchers validating every numerical methods that exists. The problem helps to understand many complex flow phenomena occurring in a cavity over wide range of Reynolds number. Due to  these still it is a popular problem. Problem can be highly recommended for beginning course of study in Fluid Mechanics/CFD, as myself found it's importance throughout my journey as a CFD Engineer.

Also, before getting into the simulation, theoretical understanding on flow circulation is necessary. Few videos below gives theoretical overview on the problem.

                      

Thanks for reading and have a great learning............  !!! ☺