Fluctuating Lift and Drag Acting on a Cylinder in a Flow at Supercritical Reynolds Numbers
The fluctuating lift and drag acting on a circular cylinder in a flow of an incompressible fluid at large Reynolds numbers were measured. Data on the root-mean-square values of the lift and drag coefficients, the extreme values of these coefficients, and their power spectra at various Reynolds numbers are presented.
In this paper, we study the asymptotical optimal solutions for the general airline revenue management problem, considering both customer cancelations and no-shows. We study a simple case where there is only one fare-class; the management controls the opening and closing of the fare-class, with the objective of maximizing the total revenue. We first develop a fluid control problem, where the customer arrival and cancelation processes are treated as deterministic, whereas the no. of no-shows is random. The optimal fluid solution is shown to have a simple structure of accepting up to a single time point t* and rejecting afterwards. We show that this policy acts as an upper bound for the MDP problem. Applying the optimal fluid solution to the stochastic environment, we show that this policy is asymptotically optimal on the fluid scaling.