CENTRE OF PRESSURE

When an aircraft is in flight it experiences several loads across its structure which is defined as pressure distribution in technical terms. The pressure varies across the fuselage and the wing structure and it is impossible to analyse it. Hence the overall pressure distribution is represented by a single aerodynamic force called center of pressure or total reaction force which lies on the chord line of the aerofoil. The center of pressure moves along the chord line when the angle of attack is altered.

At normal cruising speeds and low positive angles of attack the center of pressure is positioned on the chord line near the center of an aerofoil. With increasing angles of attack the center of pressure moves forward towards the leading edge and the magnitude of the total reaction force increases. When the aircraft reaches the stalling angle of attack the magnitude of the total reaction force reduces and the angle of attack moves towards the trailing edge.

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AIRFOIL TERMINOLOGY

Air foil Terminology What is an airfoil? How an air foil is described in modern science, what are the parameters that determines its shape? An Air foil is primary building block of an aircraft which has two edges namely leading edge and trailing edge, the straight line connecting the leading and trailing edge of the air foil is called as chord line. The line which is drawn equidistant from the upper and lower surfaces of the air foil and connecting the leading and trailing edge is called as mean camber line.The distance between the leading and trailing edge is called chord of an air foil. The maximum distance between the mean camber line and chord line is referred as maximum camber. This is one of the variables that determine the aerodynamic characteristics of the wings. Maximum thickness to chord ratio is expressed in terms of percentage. For subsonic wings the ratio is normally 12-14% Depending on the camber (curvature) of the air foil it is d

Form Drag

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AEROFORUM

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