Abstract
Abstract This thesis reports the simulations of insect flight using the immersed boundary. The major advantage of the IBM is that the computations can be performed within the Cartesian framework to mimic the complex geometry of the insect wing. Both the inertial and non-inertial coordinate systems are adopted in the computations and the predicted lift and drag coefficients are examined. In comparisons with the benchmark solutions of Wang, the non-inertial frame simulation was observed to produce more accurate results than those generated by the inertial frame. When examining the predicted vorticity fields, the wake capture and delayed stall phenomena were captured by the present predictions The influences of the Reynolds number and the phase differences on the lift and drag were also examined. The ranges of the Reynolds numbers investigated are from 78.5 to 314. It was shown that the insect can not generate enough lift force to support its flight when the Reynolds number was smaller than 78.5. The lift and drag were also shown to increase in tandem with the Reynolds number. The computations of the variations of the phase angles,, and, show that the delayed rotation produces the negative lift force. On the other hand, both the lift and drag forces generated by the advanced rotation are approximately 40% higher than those generated by the symmetric rotation.