An airfoil generates a lift of 80 N when operating in a free stream flow of 60 m/s. If the ambient pressure and temperature are 100 kPa and 290 K respectively ( specific gas constant is 287 J/kg-K), find the circulation on the airfoil.
An airfoil generates a lift of 80 N when operating in a free stream flow of 60 m/s. If the ambient pressure and temperature are 100 kPa and 290 K respectively ( specific gas constant is 287 J/kg-K), the circulation on the airfoil is
Here first we need to calculate the air density.
\(P=\rho RT
\\\rho =\frac{P}{RT}
\\=\frac{10^{5}}{287\times 290}
\\=1.2014\;kg/m^{3}\)
On applying Kutta-Joukowski theorem:
\({L}’=\rho V\tau
\\\Rightarrow \tau =\frac{80}{1.2014\times 60}
\\=1.11\;m^{2}/s\)
Therefore circulation on the airfoil is \(1.11\;m^{2}/s\).
