boundary-layer thickness at x =2.0 m in 50 m/s flow of air at 20°C and 1 atm past a flat plate. Compare your result with Equation. Assume Re x,crit =1.5x106. Problem 3 A light aircraft has tapered wing with root and tip chord-lengths of 2.2m and 1.8 m respectively and wingspan of 16m. Estimate the skin friction drag of the wing when the aircraft is travelling at 55m/s. On the upper surface the point of minimum pressure is located at 0,375 chord-length from the leading edge. The dynamic viscosity and density of air may be taken as 1.8E-5 Kg s/m and 1.2 Kg/m3 respectively Problem 4 A semi-infinite flat plate is placed in air freestream of velocity U which is parallel to the plate. Calculate (i) the boundary layer velocity profile on the plate. (ii) Boundary thickness (iii) Shear stress on the wall. (iv) Skin friction coefficient. If the plate is placed at angle of attack of 10 degree, set up only the equations for solving the velocity profile. Problem 5 A flat plate is placed in a uniform airstream of 20 m/s and zero incidence. What is the displacement thickness at the trailing edge, if the total length of the plate is 0.5m, 1m and 1.5m?.For each length, calculate de the overall drag coefficient and shear stress of the pate. Problem 6 The streamwise velocity component of a steady, incompressible, laminar, flat plate boundary layer, boundary layer thickness is approximated by the simple linear δ for and u=U for for displacement expression u=Uy/δ y<δ, y>δ. Generate expressions thickness ad momentum thickness as a function of on the linear approximation. δ, based Compare the approximate values of and to the values of and obtained from the Blasius solution.
boundary-layer thickness at x =2.0 m in 50 m/s flow of air at 20°C and 1 atm past a flat plate. Compare your result with Equation. Assume Re x,crit =1.5x106. Problem 3 A light aircraft has tapered wing with root and tip chord-lengths of 2.2m and 1.8 m respectively and wingspan of 16m. Estimate the skin friction drag of the wing when the aircraft is travelling at 55m/s. On the upper surface the point of minimum pressure is located at 0,375 chord-length from the leading edge. The dynamic viscosity and density of air may be taken as 1.8E-5 Kg s/m and 1.2 Kg/m3 respectively Problem 4 A semi-infinite flat plate is placed in air freestream of velocity U which is parallel to the plate. Calculate (i) the boundary layer velocity profile on the plate. (ii) Boundary thickness (iii) Shear stress on the wall. (iv) Skin friction coefficient. If the plate is placed at angle of attack of 10 degree, set up only the equations for solving the velocity profile. Problem 5 A flat plate is placed in a uniform airstream of 20 m/s and zero incidence. What is the displacement thickness at the trailing edge, if the total length of the plate is 0.5m, 1m and 1.5m?.For each length, calculate de the overall drag coefficient and shear stress of the pate. Problem 6 The streamwise velocity component of a steady, incompressible, laminar, flat plate boundary layer, boundary layer thickness δ is approximated by the simple linear expression u=Uy/δ for y<δ, and u=U for y>δ. Generate expressions for displacement thickness ad momentum thickness as a function of δ, based on the linear approximation. Compare the approximate values of and to the values of and obtained from the Blasius solution.
Homework_6_nove_2016(1).docx