Propeller shrouding influence on lift force of mini unmanned quadcopter

Abstract

This article discusses the lift force generated by a mini unmanned aerial vehicle. Shrouded propellers were considered and analyses of shroud influence on lift force and energy saving were done. By help of laboratory experiments and computational fluid dynamics simulations (propeller velocity varied from 1000 rpm to 6000 rpm, shroud height from 20 mm to 60 mm, gap from 3 mm to 28 mm), it was shown that the shroud diameter influenced the rotor energy consumption up to 30% at velocities of more than 4000 rpm. With the increase shroud diameter (increase of distance between shroud and propeller borders), the lifting force increased. A gap of more than 30 mm practically did not influence the lifting force. Shroud height (from 20 mm to 60 mm, gap is 28 mm) also influenced the propeller efficiency (up to 10%) on small shroud heights (up to 30 mm).  With the increase of the shroud height, the lift force decreased about 3% and then it increased up to 12%. From a value of about 50 millimetres, this influence will be unchanged but the total lifting force will be about 5% less in comparison with the force produced by propeller without shroud