According to the Newtonian theory, which of these is preserved after the impact of the incident particles?

Normal velocity

Normal momentum

Tangential momentum

Tangential velocity

Correct Answer : Tangential momentum

Explanation : When there is an incoming stream of particles on a flat plate with a free stream velocity, the normal momentum is transferred to the surface after the impact. On the other hand, the tangential momentum is preserved. This result was obtained by Newton with an assumption that the particles do not interact with each other and hence are linear.

Recently Updated in Aerodynamics Questions

Newton's theory gives much more accurate results for 2 � dimensional shapes.

True

False

Can Not Say

None of the above

Correct Answer : Option (B) : False

Explanation : For three – dimensional bodies such as a cone, Newtonian theory is generally more accurate in contrast with two – dimensional bodies like wedge. One more important property to note is that Newton’s theory gets much more accurate with increasing Mach number.

Which of these methods is not a local inclination method for computing pressure distribution?

Newtonian theory

Tangent cone theory

Tangent wedge theory

Oblique shock method

Correct Answer : Option (D) : Oblique shock method

Explanation : There are three other local surface inclination inclinations, in addition to Newtonian theory. Methods that are widely used to estimate distributions of pressure over hypersonic bodies are the tangent wedge method, tangent cone method and shock – expansion method.

As a result of chemically reacting gas, which of these features differ compared to the ideal gas?

Lift

Drag

Temperature

Pitching moment coefficient

Correct Answer : Option (D) : Pitching moment coefficient

Explanation : Chemically reactive flow in hypersonic flow determines the pitching moment over the space shuttle. The pressure on the forward part of the shuttle body is usually higher for a chemically reactive gas, and it is lower in the rearward part. This leads to a positive pitching moment of the shuttle.