Starting vortex

About: Starting vortex is a research topic. Over the lifetime, 4785 publications have been published within this topic receiving 100419 citations.

Airfoil with reduced heat load

Abstract: An airfoil with a reduced heat load for use in either a turbine or a compressor of a gas turbine engine comprises having at least one heat reducing dimple on the body of the airfoil or on the associated endwall of the airfoil. The body of the airfoil is comprised of a leading edge, a trailing edge, a pressure side and a suction side. The length of the heat reducing dimple in the expected direction of hot gas stream flow is at least equal to or greater than the width transverse to such direction. The heat reducing dimple is located on the airfoil or endwall so as to reduce the heat load as the hot gas stream flow passes from the leading edge to the trailing edge.

On steady and pulsed low-blowing-ratio transverse jets

Abstract: The present experimental and numerical study focuses on the vortical structures encountered in steady and pulsed low-blowing-ratio transverse jets ( ), a configuration hardly discussed in the literature. Under unforced conditions at low blowing ratio, a stable leading-edge shear-layer rollup is identified inside the jet pipe. As the blowing ratio is increased, the destabilization and evolution of this structure sheds light on the formation mechanisms of the well-known transverse jet vortical system. A discussion on the nature of the counter-rotating vortex pair in low-blowing-ratio transverse jets is also provided. Under forced conditions, the experimental observations support and extend numerical results of previous fully modulated jet studies. Large-eddy simulation results provide scaling parameters for the classification of starting vortices for partly modulated jets, as well as information on their three-dimensional dynamics. The counter-rotating vortex pair initiation is observed and detailed in both Mie scattering visualizations and simulations. The observations support a mechanism based on stretching of the starting vortical structures because of inviscid induction and partial leapfrogging. Two modes of cross-flow ingestion inside the jet pipe are described as the pulsed jet cycles from high to low values of blowing ratio.

Translation Effects on Simulated Tornadoes

Abstract: A simulation of tornadoes translating over the ground was carried out in a modified Ward simulator The purpose was to investigate the effects of translation on tornado dynamics The results are as follows: • Secondary vortexes were found to be generated by the relative motion between the main vortex and rough “ground” The secondary vortexes trail the primary vortex Apparently they feed off the energy of the primary vortex, and achieve a momentary transition state from a single vortex to multiple vortexes • The core radius increases with swirl ratio and decreases with surface roughness Translation causes a local increase in swirl ratio, increasing the core size over that of a stationary vortex • The central pressure drop increases with swirl ratio during translation Translation also causes a steeper pressure gradient on the trailing side of the vortex core A similar characteristic tilt on the trailing side of the pressure profile has been noted on barograms for real tornadoes