Aerodynamics of Military Fighter Jets

Aerodynamics of Military Fighter Jets

Introduction

Aerodynamics is the part of physics that studies the effects of air and gases on the movement of solids the aerodynamics describes the behavior of a body moving in the air and its resistance to progress. A streamlined body offers little resistance to the air. In aviation, we search for the best compromise between lift that promotes theft and drag due to air friction on the surface of the device that is opposed (and in particular increased fuel consumption). Unlike a hot air balloon, a stationary aircraft remains on the ground and must move relative to the ambient air to fly. This movement creates surfaces of the aircraft (wing, fuselage, empennage, drift) forces that allow it to take off and remain in the air. To understand why an airplane flies, we study the behavior of an aircraft in a wind tunnel.

Modeling

An aircraft traveling at a speed relative to the ambient air has an aerodynamically like an airplane at rest on which blows a wind speed as well. This principle is used in wind tunnels. This is known as relative wind: reasoning on an airplane or traveling on a plane "blown" is neighbors.

The flow of air around the plane can be modeled by "power tubes", kind of variable section tubes, which form "follows" the flow. Is arrived at in a wind tunnel materialize with fine jets of smoke placed upstream of the plane.

With increasing speed, the compression of the air forms of shock waves that affect the structure of the device. In subsonic flight (below the speed of sound), the areas of pressure air moving at the speed of sound have time to dissipate around the unit. When the flow of air around the aircraft reaches the speed of sound (the latter depends on the altitude and temperature), there occurs a phenomenon of concentration waves whose accumulation overpressure form a veritable wall of compressed air. This accompanies the aircraft as it exceeds the speed of sound, so the "bang" that can be heard is not crossing the sound barrier. The "sonic boom" is actually arriving at the ground of the high pressure air (Smith, 2001).

The Mach measures the ratio of the speed of the aircraft by the speed of sound. A Mach 1, the aircraft flies at a speed of sound.

Air flow around an object

When an aircraft is placed in an air stream, the air bypasses the wing from the top and from the bottom. Opposed to the lower surface which means the lower surface of the wing of an airplane, upper designates its upper surface. While the lower surface may be flat, concave or convex, the upper surface is always convex. It is important that the air flows faster on the underside , that is to say, it has a greater distance to travel at the same time. Application of Bernoulli's principle, it is then exerted on the upper pressure less than that exerted on the underside : it is this pressure ...