4444

Which of the following is true about the Bernoulli’s Principle?

• dynamic pressure is maximum at stagnation point

• total pressure across the flow direction is unchanged from initial to final flow point of a fluid.

• dynamic pressure decreases as static pressure decreases

• dynamic pressure increases as static pressure increases

Which of the following is true in able to attain equal Reynold's Number of a fullscale airplane (actual flight) and a model scale (tested inside the wind tunnel).

• The velocity in the wind tunnel must be much greater than the actual flight.

• The velocity in the wind tunnel must be much lesser than the actual flight

• The velocity in the wind tunnel must be equal to the velocity of the actual flight

• The density in the wind tunnel must be equal to SSLC.

Which of the following is true?

• As the angle of attack increases the point of flow separation moves farther aftward

• As the angle of attack increases the point of flow separation moves forward but not exceeding the quarter chord

• As the angle of attack increases the point of flow separation moves farther forward

• As angle of attack increases the point of flow separation moves to the lower surface of the wing

An aircraft flying between the boundaries of stratopause and tropopause descends at a constant true airspeed. Its Mach No. will

• not change

• decrease

• increase

• increase then decrease

Which of the following is true?

• Minimum velocity is achieve at critical angle of attack

• Maximum velocity corresponds to diving configuration

• Minimum IAS is measured using static ports

• Maximum velocity increases as the critical angle of attack increases

Which of the following wing / airfoil feature contributes to the increase in critical Mach number?

• Low thickness-chord ratio

• Maximum thickness point is well aft. at about quarter-chord

• Large leading edge radius

• Symmetrical wing sections

If the continuity equation is applicable, what will happen to the air density (rho) if the cross-sectional area of a tube increases (high speed, subsonic flow)

• rho1 < rho2

• rho1 > rho2

• rho1 = rho2

• none of the above

Which of the following statements, about a venturi in a subsonic airflow are correct? (1) the dynamic pressure in the undisturbed flow and in the throat are equal. (2) the static pressure in the undisturbed flow and in the throat are equal.

• 1 and 2 are correct

• 1 is correct and 2 is incorrect.

• 1 and 2 are incorrect.

• 1 is incorrect and 2 is correct

Which of the following is true about stalling of a swept wing? (1) Maximum lift coefficient is reached first at the tip. (2) The boundary layer tends to drift outwards thus encouraging flow separation.

• 1 is correct

• 1 and 2 are correct

• 2 is correct

• 1 and 2 are incorrect

Which of the following is true? (1) Pressure coefficient at stagnation point is equal to 1. (2) A positive pressure coefficient implies pressure greater than the freestream value.

• 1 is correct

• 1 and 2 are correct

• 2 is correct

• 1 and 2 are incorrect