飞行原理英文填空
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1. Most airplanes have small hinged sections on the trailing edge of the elevatorsand sometimes on the rudder called trim tabs. These tabs move in the opposite direction to the control surface.P2 2. The hinged portions on the inboard part of the trailing edge of the wings are the flaps. These are used to produce greater lift at low speeds and to provide increased drag on landing.P2 3. The tail dragger has the main landing gear forward of the center of balance and a small steerable wheel at the tail.P3 4. The chord is used for determining the geometric angle of attack and for determining the area of a wing.P3 5. A symmetric airfoil has no camber.外倾角P3 6. Rectangular矩形 wings have a taper ratio of one, and delta三角形wings have a taper of zero.P4 7. An airplane moves in these dimensions call roll, pitch, and yaws, the ailerons control rotation about the roll axis.P8 8. The key point of the popular description of lift is that the air accelerates使。。增速 over the top of the wing.P15 9. The aeronautical engineers often use a mathematical concept calledcirculation to calculate the acceleration of the air over the wing.P16 10. In the physical description of lift is recognized as a reaction force, that is,wings develop lift by diverting air down.P17 11. A body at rest will remain at rest, and a body in motion will continue in straight-line motion unless subjected to an external applied force.P18 12. The Coanda effect has to do with the bending of fluids around an object.P19 13. In a fluid without, viscosity, such as superfluid helium, a wing could not fly.P21 14. The wing develops lift by transferringmomentum to the air. Momentum is mean times velocity.P24 15. If the speed of an airplane were to double, the lift would be four time. 16. Parasitic power varies as speed cubed.P34 17. Parasitic drag varies as speed squared.P34 18. A symmetric wing would have to be attached at an ”incident angle” so that the fuselage is at a zero angle to the wind while the wing is at some positive angle of attack.P46 19. A wing with sufficient camber can be selected such that when the leading and trailing edges are aligned at cruise the lift balances the weight.P46 20. A thick wing can result in a large wake, resulting in high parasiticdrag, even at zero angle of attack.P47 21. The sharp wing goes from maximum lift to full stall with a very small change in angle of attack.P47 22. STOL(short takeoff and landing) aircraft have very fat, round leading edges.P48 23. The wing loading is the ratio of wing area to weight of the airplane.P50 24. The higher the wing loading the higher the stall speed.P50 25. A high aspect ratio wing can use a smaller engine and needs less takeoff and landing distance than a low aspect ratio wing.P51 26. The primary motivation behind swept wings is to reduce drag at higher cruise speeds.P53 27. A wing swept back is generally more stable than a wing without sweep.P53 28. Atapered wing has a shorter chord at the tip than at the root.P54 29. One method of tailoring the lift distribution on the wing is to twist the wing, with the angle of attack greater at the root than at the tip. Another term for this type of twist is washout.57 30. One method of tailoring the lift distribution on the wing is to twist the wing, with the angle of attack greater at the root than at the trip. Another term for this type of twist is washout.P57 31. Dihedral adds stability because the adverse yaw results in a net reduced angle of attack on the upper wing, and an increased angle of attack on the lower wing.P58 32. If a wing can reach a higher angle of attack before stalling, it will be able to take off and land at lower speeds or carry heavier loads. P65 33. Parasite drag is composed of two parts. In chapter 2 the effect of friction +skin friction+ was discussed. Also mentioned was form drag.P66 34. The most common high-lift device is the wing flap. The next most common is to add leading-edge devices called slot and salts.P69 35. Slots and Slats allow the high-energy air from below the wing to flow to the upper surface of the wing.P72 36. If it initially tends to return toward equilibrium, it has positive static stability.P78 37. If an airplane tends initially to move away from equilibrium when disturbed, it has negative static stability.P79 38. Dynamic stability can be further divided into oscillatory and non-oscillatory modesP79. 39. Longitudinal stability involves the motion of the airplane controlled by the elevators.P80 40. If the CG is too far forward, these may not be enough elevator authority to raise the nose, either for takeoff or to flare for landing.P81 41. Airplanes ordinarily have little resistance to roll inputsP82 42. If you bank a few degrees in coordinated flight and let go of the controls, most airplane show neutral static stability in roll.P82 43. The main function of the vertical stabilizer is to help the airplane weathervane and keep the nose pointed into the direction of flight.P85 44. If an airplane has strong directional stability relative to its lateral stability, it may display spiral instability.P87 45. The mild divergence caused by spiral instability is usually easy to correct, but can lead to the graveyard spiral if allowed to develop.P88 46. The difference between the engine power and the propulsive power we will call called the wasted power.P95 47. As the airplane flies faster, the wind due to the forward speed reduces the angle of attack of the propeller.P99 48. Transonic refers to speeds approaching Mach 1.P117 49. There is an additional element in supersonic aerodynamics that does not exist in subsonic aerodynamics. This is the formation of shock waves.P118 50. In supersonic flight a shock wave occurs when air must suddenly change speed and\or direction.P119 51. Before the shock wave, the air is traveling at greater than Mach1. Behind a normal shock wave, the air is subsonic and the air’s density has increased.P119 本文来源：https://www.wddqw.com/doc/ff8ea10f79563c1ec5da713f.html