tailieunhanh - Introduction to Aerospace Engineering Formulas

ần nhất định để xác định khả năng của phần được sản xuất bằng máy reconfigurable đặc biệt từ một điểm kỹ thuật của. Ngoài ra tính khả thi của quá trình từ một điểm kinh tế của phân tích. Sau đó, hệ thống xác định vị trí thích hợp của phần xem xét chi tiết các tính năng gia công và các hoạt động cần thiết. | Introduction to Aerospace Engineering Formulas 1 Aerodynamics Formulas Definitions p The air pressure. Pa N m2 p The air density. kg m3 g The gravitational constant. Value at sea level is kg N kg h The height above the earth surface. m V The speed of the airplane relative to the air. m s pt The total pressure. Pa N m2 p0 The static pressure. Pa N m2 S The wing surface. m2 L The lift force. N CD The lift coefficient. no unit D The drag force. N CD The drag coefficient. no unit CDi The induced drag coefficient. no unit e The Oswald factor. Usually has a value between and no unit A The aspect ratio. no unit b The wing span from left wing tip to right wing tip so it s not just the length of one wing . m Dj The induced drag. no unit CD0 The friction and pressure drag coefficient. no unit M The Mach number. no unit a The speed of sound. 340m s at sea level m s Re The Reynolds number. no unit L A characteristic length. Often the length of an object. m p The viscosity of the air. Normal air has viscosity X 10-6kg ms kg ms W The weight of the aircraft. N T The thrust of the aircraft. N Lw The wing loading. Pa N m2 n The load factor. no unit 1 Two-dimensional aerodynamics formulas The pressure in a certain part of the atmosphere is equal to the weight of the air column on top. The formula describing this statement is known as the hydrostatic equation dp pg dh An equation which looks a bit like the previous equation is the Euler equation dp pV dV So if we integrate this equation we find bernoulli s equation p 2 pV2 C Where C is a constant. So p 1 pV2 is constant for any 2 points along a streamline. Using this formula the airspeed can be calculated Vo 2pt pp Bernoulli s equation states that dp d 2pV2 . By integrating that over the wing surface and implementing a constant the following formula can be found L Cl 1 pV 2S Similar to this also the drag force can be calculated D Cd 1 pV 2S Induced Drag However the previously .