Caepro Technologies CFD Engineer Interview Questions, Process, and Tips

Boundary layer is the layer of fluid adjacent to a solid surface where the flow velocity changes from zero at the surface to the free stream velocity.

• Boundary layer is a region in a fluid flow where viscous effects are significant.

• It is characterized by a gradual increase in flow velocity from the solid surface to the outer flow.

• The boundary layer thickness depends on the Reynolds number and the surface roughness.

• There...read more

Common turbulent models in CFD include k-epsilon, k-omega, and Large Eddy Simulation (LES).

• k-epsilon model is widely used for industrial applications due to its simplicity and computational efficiency.

• k-omega model is known for its ability to handle adverse pressure gradients and near-wall turbulence.

• Large Eddy Simulation (LES) is used for resolving large-scale turbulent structures in high Reynolds number flows.

• Reynold...read more

Aerodynamic refers to the study of the motion of air and other gases, while hydrodynamic refers to the study of the motion of liquids, primarily water.

• Aerodynamics deals with the flow of air around objects, such as airplanes, cars, and buildings.

• Hydrodynamics focuses on the behavior of liquids, including water, in motion, such as in rivers, oceans, and pipes.

• Both fields are crucial in designing efficient vehicles, stru...read more

Mesh dependent test in CFD is a test to determine the sensitivity of the simulation results to changes in the mesh resolution.

• Mesh dependent test involves running the CFD simulation with different mesh resolutions to see how the results vary.

• It helps in assessing the accuracy and reliability of the simulation results based on the mesh quality.

• The test is important to ensure that the simulation results are not heavily i...read more

Steady state is when a system's variables do not change over time, while transient state is when variables change with time.

• Steady state: system variables remain constant over time

• Transient state: system variables change with time

• Example: A cup of hot coffee cooling down to room temperature is a transient state process

• Example: A refrigerator maintaining a constant temperature is a steady state process

Velocity and thermal boundary conditions for outer flow over flat plate and inner flow through pipe.

• Outer flow (flow over flat plate): Velocity boundary condition - free stream velocity parallel to the plate, Thermal boundary condition - constant temperature at the plate surface

• Inner flow (flow through pipe): Velocity boundary condition - parabolic velocity profile, Thermal boundary condition - constant heat flux at th

Relaxation factor in CFD controls the rate at which the solution converges towards the final solution.

• Relaxation factor is a parameter used in iterative methods to control the rate of convergence.

• A higher relaxation factor can speed up convergence but may lead to instability.

• Conversely, a lower relaxation factor can improve stability but may slow down convergence.

• Optimal relaxation factor varies depending on the proble...read more

Y+ is a dimensionless wall distance used in CFD to determine the appropriate mesh resolution near the wall.

• Y+ is used to ensure accurate modeling of boundary layer flow near walls.

• It is calculated as the ratio of the distance from the wall to the first cell center to the wall shear stress.

• Y+ values less than 1 indicate a viscous sublayer, while values greater than 30 indicate a fully turbulent flow.

• Properly resolving Y...read more

The governing equations solved in CFD include the Navier-Stokes equations, continuity equation, and energy equation.

• Navier-Stokes equations describe the motion of fluid substances.

• Continuity equation ensures mass conservation within the fluid domain.

• Energy equation accounts for the transfer of thermal energy within the fluid.

• Other equations like turbulence models may also be solved depending on the simulation requireme

The equations governing CFD are based on fundamental laws of physics.

• Based on conservation of mass, momentum, and energy

• Navier-Stokes equations are fundamental in fluid dynamics

• Incompressible flow assumes constant density

• Reynolds-averaged Navier-Stokes (RANS) equations are commonly used

I am impressed by your company's innovative projects and collaborative work environment.

• I admire the cutting-edge technology and projects your company is involved in.

• I value the collaborative work environment that your company promotes.

• I am excited about the opportunity to contribute to a team of talented professionals.

Seeking new challenges and growth opportunities in a different work environment.

• Looking for new challenges and opportunities for professional growth

• Interested in exploring different work environments and cultures

• Seeking a role with more responsibilities and learning opportunities

I have a strong background in CFD analysis, with experience in complex simulations and problem-solving skills.

• I have a Master's degree in Mechanical Engineering with a focus on CFD

• I have completed multiple projects involving CFD simulations for aerodynamics and heat transfer

• I am proficient in using software like ANSYS Fluent and OpenFOAM

• I have a track record of delivering accurate and timely results in CFD analysis