Aerodynamics Multiple Choice Questions & Answers on “Flow over Sphere”.
1. Is uniform flow around a sphere is obtained?
a) True
b) False
Answer: a
Clarification: Numerical solutions of the transient uniform flow around a sphere are obtained. The transition takes place between an initial potential flow and a fully developed viscous field. The fluid is incompressible and homogeneous around the sphere.
2. Is flow around the sphere is incompressible and homogeneous?
a) False
b) True
Answer: b
Clarification: The fluid is incompressible, homogeneous and its flow is governed by the complete more naive stokes equations. The range of Reynold number studied id 1-1000, where a recirculatory wake appears and the nonlinear terms are essential.
3. Is recirculatory wake appears at Re 1-1000?
a) False
b) True
Answer: b
Clarification: The range of Reynolds number studied at Re 1-1000 .where a recirculatory wake appears and the nonlinear terms are essential, that is they cannot be neglected or approximated. The flow is assumed to be axisymmetric through this range.
4. Is flow is assumed to be axisymmetric?
a) True
b) False
Answer: a
Clarification: The flow is assumed to be axisymmetric throughout this range. A timed pent stream function vorticity formulation is adopted. The solution is obtained by constructing a finite difference approximation to the vorticity transport equation on an expanding spherical polar grid system.
5. Is vorticity transport is obtained by constructing a finite difference approximation?
a) True
b) False
Answer: a
Clarification: The is obtained by constructing a finite difference approximation to the vorticity transport equation on an expanding spherical polar grid system. Central difference of second order accuracy both in time and space is utilized.
6. Is second order accuracy occurs at a time?
a) True
b) False
Answer: a
Clarification: Central differencing of second order accuracy both in time and space is utilized. Experiments with numerical stability show an appreciable deviation from linearized stability analysis due to the large gradients of vorticity in the field.
7. Is large gradients of vorticity is applied at linearized stability?
a) True
b) False
Answer: a
Clarification: The linearized stability analysis due to the large gradients of vorticity in the field. Quantitative physical results are obtained. The geometrical parameters characterizing the recirculatory wake compare favorably with those recorded in physical experiments.
8. Is flow field around a sphere is uniform?
a) True
b) False
Answer: a
Clarification: The flow field around a sphere in a uniform flow has been analyzed numerically for conditions corresponding to the subcritical and supercritical regimes spanning a wide range of Reynolds number particular attention has been devoted to assessing predictions.
9. Is skin friction drag is formed due to pressure distribution?
a) True
b) False
Answer: a
Clarification: The pressure distribution, skin friction, and drag as well as to understanding the changes in the wake organization and vortex dynamics with the Reynolds number. The unsteady turbulent flow is computed using detached eddy simulation.
10. Is large eddy simulation will occur for both subcritical and supercritical solution?
a) True
b) False
Answer: a
Clarification: The large eddy simulation in the regions away from solid surfaces. For both the subcritical and supercritical solutions, the agreement with experimental measurements for the mean drag and pressure distribution over the sphere is adequate.