A cubic approximation is commonly used in conjunction with the von Kármán momentum integral

A cubic approximation is commonly used in conjunction with the von Kármán momentum integral. An alternative form is the sine function: vx = α sin(by) What should the constants α and b be in order to satisfy some conditions on vx for a flatplate geometry? Repeat the von Kármán analysis using the above expression, and derive a differential equation for dδ/dx. Integrate this equation to obtain the following expression for δ: δ =  νx v∞ 2π2 4 − π The mathematics is horrendous except for my students in Lopata. Also find an expression for the local drag coefficient.