The flow around heated cylinders has already been investigated by many researchers. Object of the present examination is an electrically heated circular cylinder placed in a parallel flow in a wind tunnel. The experimental tests were carried out at low Reynolds numbers (Re<200), thus the flow field was approximately two dimensional (same flow in every normal plan of the heated circular cylinder...

We report upon an experimental study of internal gravity waves generated by the large-amplitude vertical oscillations of a circular cylinder in uniformly stratified fluid. Quantitative measurements are performed using a modified synthetic schlieren technique for strongly stratified solutions of NaCl or NaI. The oscillatory forcing leads to the development of turbulence in the region bounding th...

The character of the boundary layer noise and ambient tunnel noise are of interest in the experimental study of laminar to turbulent transition. The instability mechanism in hypersonic flow over slender bodies is the acoustic mode. A number of investigations of flow over a slender cone in high-enthalpy facilities have been performed; however, measurements of the boundary layer noise and ambient...

The influence of additives inducing viscoelasticity in diesel fuel, on the in-nozzle cavitation evolution and expelled spray morphology has been quantified by high-speed, diffused back-light schlieren imaging applied to two single-hole true-scale transparent injectors straight tapered orifice layouts (so-called Spray C D engine Combustion Network), as well a five-hole configuration (Spray M). M...

The dissociation of diacetyl dilute in krypton has been studied in a shock tube using laser schlieren densitometry at 1200-1800 K and reaction pressures of 55 +/- 2, 120 +/- 3, and 225 +/- 5 Torr. The experimentally determined rate coefficients show falloff and an ab initio/Master Equation/VRC-TST analysis was used to determine pressure-dependent rate coefficient expressions that are in good ag...

The results of experiments on Richtmyer–Meshkov instability growth of multimode initial perturbations on an air–sulfur hexafluoride (SF6) interface in a conical geometry are presented. The experiments are done in a relatively larger shock tube. A nominally planar interface is formed by sandwiching a polymeric membrane between wire-mesh frames. A single incident shock wave ruptures the membrane ...

The feasibility of digital holographic interferometry using a CW laser @ 532 nm and a Photron APX camera is demonstrated in the F4-ONERA hypersonic wind tunnel. This optical technique is used to point out the possible combustion of a small hydrogen jet in the shock layer developed on the model. The optical technique generates in the field under analysis, interference micro-fringes which are use...