JNTU
JNTU B.Tech III COMPUTATIONAL AERODYNAMICS Previous Question Paper (May - 2019 - R15)
Note: This question paper contains two parts A and B. Part A is compulsory which carries 25 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit. Each question carries 10 marks and may have a, b, c as sub questions.
Part A
What steps are involved in solving a typical CFD problem?
Answer
- Pre-processing: Geometry definition, grid generation, and defining boundary conditions.
- Solver: Selection of numerical schemes and solving discretized governing equations.
- Post-processing: Visualization and analysis of flow field data.
Define substantial derivative and explain its physical significance.
Answer
The substantial derivative represents the time rate of change of a fluid property following a fluid element moving through the flow field. It is defined as D/Dt = ∂/∂t + (V · ∇). Its physical significance is that it accounts for both the local change at a fixed point and the convective change due to the motion of the fluid particle.
What are characteristic lines?
Answer
Sign in to view the complete answer paper.
Explain Dirichlet and Neumann boundary conditions for elliptic partial differential equations.
Answer
Sign in to view the complete answer paper.
What is Courant number and what is its function?
Answer
Sign in to view the complete answer paper.
Differentiate between structured and unstructured grids.
Answer
Sign in to view the complete answer paper.
What steps are required in setting up the finite volume method?
Answer
Sign in to view the complete answer paper.
List out the differences between finite difference and finite volume methods.
Answer
Sign in to view the complete answer paper.
Differentiate between staggered and collocated arrangements of grids in CFD.
Answer
Sign in to view the complete answer paper.
Distinguish between SIMPLE and SIMPLER pressure correction algorithms.
Answer
Sign in to view the complete answer paper.
Part B
Derive integral forms of continuity equation using flow models of control volume fixed in space and control volume moving with fluid.
Answer
Sign in to view the complete answer paper.
Explain shock capturing and shock fitting approaches of handling shocks in CFD with figures. Discuss their relative advantages and disadvantages.
Answer
Sign in to view the complete answer paper.
Describe the general method of classifying a system of quasi-linear partial differential equations using Eigen value method.
Answer
Sign in to view the complete answer paper.
Discuss the concepts of domain of dependence and range of influence for hyperbolic equations using a sketch.
Answer
Sign in to view the complete answer paper.
Explain Parabolized Navier-Stokes (PNS) model for viscous flows and discuss its advantages.
Answer
Sign in to view the complete answer paper.
Describe explicit and implicit approaches to the numerical solution of fluid flows using sketches and illustrate them for one dimensional heat conduction equation:
Answer
Sign in to view the complete answer paper.
Describe different types of body-fitted and multi-block grids with the help of sketches.
Answer
Sign in to view the complete answer paper.
Discuss cell-centred and cell-vertex approaches of finite volume method with suitable diagrams.
Answer
Sign in to view the complete answer paper.
Discuss the general formulation of a numerical scheme based on finite volume method.
Answer
Sign in to view the complete answer paper.
Explain MacCormack’s technique for time marching solution of two-dimensional unsteady Euler equations.
Answer
Sign in to view the complete answer paper.
Discuss the numerical steps involved in the pressure correction algorithm SIMPLE.
Answer
Sign in to view the complete answer paper.