Unsteady helicopter rotor aerodynamics are complicated. This paper reviews some of the fundamentals and newer developments of unsteady helicopter aerodynamics. Rotor flow is beautiful and complex. Visualizing rotor flow allows for an appreciation of the following theories and solution attempts as well as nature’s complexities. The flow through a helicopter rotor with forward motion is shown in ...

The resurgence in popularity of subsonic .30 caliber bullets in 300 Whisper and 300 Blackout has led to the development of bullets that will expand at subsonic velocities. The availability of these bullets has led to questions about the applicability of this caliber for wildlife damage management. We conducted a preliminary investigation to determine the potential of subsonic .30 caliber bullet...

sonic Unsteady Lifting Surfaces," AIAA Journal, Vol. 22, No. 2, 1984, pp. 179-186. Tewari, A., "Nonplanar Doublet-Point Method in Supersonic Three-Dimensional, Unsteady Aerodynamics," M.S. Thesis, Univ. of Missouri-Rolla, Rolla, MO, 1988. Tewari, A., "New Acceleration Potential Method for Supersonic Unsteady Aerodynamics of Lifting Surfaces, Further Extension of the Nonplanar Doublet Point Meth...

This report reviews the available literature on the aerodynamics of wind turbines and wind farms. Firstly, two introductory chapters are devoted to the physics of the flow around a wind turbine and the existing engineering models for blade and wake aerodynamics. The focus of this work is however on the numerical modeling of wakes. The difficulties in solving the Navier-Stokes equations are disc...

High angle of attack aerodynamics is inherently associated with: • separated flows, and thus nonlinear aerodynamics > one of the key aspects is the interaction of components, and in particular, vortex flows (vortex bursting is also an important effect) • heavily dependent on wind tunnel testing • connected with flight simulation to ensure good handling qualities > this means that large amounts ...

The long-time behavior of the solution of the system θτ−απτ = Ω(θ), πτ−θτ = πξξ is investigated. Such a system is related to the modeling of detonation waves subjected to strong hydraulic resistance. We establish that some initial conditions yield decay (failure of ignition) while for other initial conditions our results strongly suggest convergence to traveling waves (successful ignition).

ABSTRACT The rate of subsonic wind accretion (accretion on a point Newtonian mass moving through uniform gas) is shown to be independent the velocity and equal spherical Bondi – for adiabatic index 5/3. A (very accurate) numerical calculation flow, confirming this result, also presented.