Questions from Thermal Fluid Science

Q: At winter design conditions, a house is projected to lose heat

At winter design conditions, a house is projected to lose heat at a rate of 60,000 Btu/h. The internal heat gain from people, lights, and appliances is estimated to be 6000 Btu/h. If this house is to...

Q: Both the lift and the drag of an airfoil increase with an

Both the lift and the drag of an airfoil increase with an increase in the angle of attack. In general, which increases at a higher rate, the lift or the drag?

Q: Why are flaps used at the leading and trailing edges of the

Why are flaps used at the leading and trailing edges of the wings of large aircraft during takeoff and landing? Can an aircraft take off or land without them?

Q: Why is the contribution of viscous effects to lift usually negligible for

Why is the contribution of viscous effects to lift usually negligible for airfoils?

Q: Air is flowing past a symmetrical airfoil at an angle of attack

Air is flowing past a symmetrical airfoil at an angle of attack of 5°. Is the (a) lift and (b) drag acting on the airfoil zero or nonzero?

Q: Air is flowing past a spherical ball. Is the lift exerted

Air is flowing past a spherical ball. Is the lift exerted on the ball zero or nonzero? Answer the same question if the ball is spinning.

Q: What is the difference between streamlined and bluff bodies? Is a

What is the difference between streamlined and bluff bodies? Is a tennis ball a streamlined or bluff body?

Q: What is the effect of wing tip vortices (the air circulation

What is the effect of wing tip vortices (the air circulation from the lower part of the wings to the upper part) on the drag and the lift?

Q: What is induced drag on wings? Can induced drag be minimized

What is induced drag on wings? Can induced drag be minimized by using long and narrow wings or short and wide wings?

Q: Explain why endplates or winglets are added to some airplane wings.

Explain why endplates or winglets are added to some airplane wings.