Three different cyclist positions were evaluated with Computational Fluid Dynamics (CFD) and wind-tunnel experiments were used to provide reliable data to evaluate the accuracy of the CFD simulations. Specific features of this study are: (1) both steady Reynolds-averaged Navier-Stokes (RANS) and unsteady flow modelling, with more advanced turbulence modelling techniques (Large-Eddy Simulation -...

A method of scaling is described that easily converts the aeroelastic equations of motion of a full-sized aircraft into ones of a wind-tunnel model. To implement the method, a set of rules is provided for the conversion process involving matrix operations with scale factors. In addition, a technique for analytically incorporating a spring mounting system into the aeroelastic equations is also p...

This report describes the formulation of a model of the dynamic behavior of the Benchmark Active Controls Technology (BACT) wind tunnel model for active control design and analysis applications. The model is formed by combining the equations of motion for the BACT wind tunnel model with actuator models and a model of wind tunnel turbulence. The primary focus of this report is the development of...

The Hy-V project will conduct the first-ever mode-transition flight-test for a dual-mode hypersonic scramjet, which will occur at approximately 90,000 feet onboard a sounding rocket. At altitude, atmospheric conditions and inlet flow speed will match the flow conditions simulated in the UVA Aerospace Research Laboratory (ARL) hypersonic wind tunnel. Geometric similarity between the wind tunnel ...

Results are presented from wind tunnel simulations of gaseous pollutant dispersion in the atmospheric convective boundary layer (CBL) capped by a temperature inversion. The experiments were performed in the thermally stratified wind tunnel of the University of Karlsruhe, Germany. In the tunnel, the case of horizontally evolving, sheared CBL is reproduced. This distinguishes the employed experim...

Tonal, non-vocal sounds are widespread in both ordinary bird flight and communication displays. We hypothesized these sounds are attributable to an aerodynamic mechanism intrinsic to flight feathers: aeroelastic flutter. Individual wing and tail feathers from 35 taxa (from 13 families) that produce tonal flight sounds were tested in a wind tunnel. In the wind tunnel, all of these feathers could...

An investigation is presented of Mach 12 flow over a wind tunnel model of a tether connecting an aerobraking spacecraft to an inflatable drag device. The study was undertaken to support numerical simulations employed in the design of a “ballute” (balloon-parachute) aerobraking device currently being developed by Ball Aerospace and NASA. The attachment point of the tether to the ballute is subje...

An automatic rotor trim control system was developed and successfully used during a wind tunnel test of a full-scale UH-60 rotor system with Individual Blade Control (IBC) actuators. The trim control system allowed rotor trim to be set more quickly, precisely and repeatably than in previous wind tunnel tests. This control system also allowed the rotor trim state to be maintained during transien...

This paper explored the effect of building shape on the wind-induced response of a structure through a comprehensive investigation of wind tunnel studies performed at Rowan Williams Davies and Irwin, Inc. (RWDI). The study focused on buildings with foot prints of square, circular, triangular, rectangular and elliptical shapes. Seed buildings were selected from an inventory of structures previou...

in this article, an algorithm for designing of a supersonic wind tunnel injection nozzle ejector is presented and based on this algorithm, a new ejector is designed for a supersonic wind tunnel. the injection nozzle consists of a volute, a nozzle, and several vanes. designed injection nozzle is simulated numerically, and the results are compared with the present injection nozzle. the results sh...