# Find circulations around the cylinder.

Lift per unit span of a spinning circular cylinder in a free stream with velocity  of 50 m/s is 8 N/m at a standard sea level conditions.Find the circulation $$‘\tau ‘$$ around the cylinder.

Asked on 28th December 2018 in
Lift per unit span is given as $${L^\prime} = {\rho _\infty }{V_\infty }\tau$$$\tau = \frac{{{L^\prime}}}{{{\rho _\infty }{V_\infty }}} = \frac{8}{{\left( {1.23} \right)\left( {50} \right)}} = 0.13\,{m^2}/s$