Radiation of sound from a simplified model of a buried nozzle with bypass flow is studied. More precisely, a semi-infinite duct (the inner nozzle) is situated inside a larger semi-infinite duct. The exit plane of the larger duct either coincides with the exit plane of the smaller duct, or extends beyond it. Differences in the piece-wise subsonic mean flow velocity, density and temperature are t...

The nanoparticle transportation and Brownian diffusion in planar jet flow is simulated via large eddy simulation in this work. To thorough compare the Brownian diffusion with different particle size, we computed three particle diameter dp = 1 nm, 10 nm and 50 nm in one simulation process simultaneously. The numerical results showed that at the flow developing stage, the particle mass concentrat...

The next-generation of small satellites (‘nanosats’) will feature masses <10 kg and require miniaturised propulsion systems capable of providing extremely low levels of thrust. The emergence of viscous, thermal and/or rarefaction effects on the micro-scale can significantly impact the flow behaviour in supersonic micronozzles resulting in performance characteristics which differ substantially f...

A jet is a stream of one fluid entering another at high speed. In the simplest classical model of jet flow, the geometry is two-dimensional, gravity and viscosity are ignored, the moving fluid is a liquid, and the stationary fluid is a gas whose influence is assumed negligible. The description of this idealized flow can be reduced to a problem of complex analysis, but, except for very simple no...

A solid object impacting on liquid creates a liquid jet due to the collapse of the impact cavity. Using visualization experiments with smoke particles and multiscale simulations, we show that in addition, a high-speed air jet is pushed out of the cavity. Despite an impact velocity of only 1 m/s, this air jet attains supersonic speeds already when the cavity is slightly larger than 1 mm in diame...

Little knowledge exists concerning the atomization mechanisms and dispersion of flashing sprays in dermatologic cooling. This study examines flashing of a high superheat fluid flowing through micro tube nozzles resembling current medical devices. A one-dimensional, semi-empirical model of refrigerant flow through capillary tubes is used to quantify internal flow characteristics. These results p...

An empirical frictional correction factor to the isentropic nozzle model has been developed for application to leakage modeling in scroll, rotary and other similar compressors. This correction factor is derived by calculating the leakage mass flow with a compressible, variable area, real gas properties model and then correlating the ratio of this flow to the isentropic nozzle model prediction. ...

The dynamics of major flow structures were studied in a gas turbine model combustor for perfectly premixed swirlstabilized flames under a variety of reacting and non-reacting conditions using high-repetition-rate laser diagnostics. The studied combustor is a target case for the International Workshop on Advanced Measurement Techniques and Computational Methods for Premixed and Partially Premixe...

Electromagnetic forces are an important tool to control fluid flow in the mold, combined with other casting conditions, nozzle, and mold geometry. Methods include static magnetic fields (local and ruler EMBr), and time-varying magnetic fields, such as electromagnetic stirring, (EMS), multi-mode EMS, electromagnetic level stabilizers (EMLS), and electromagnetic level accelerators (EMLA). Optimal...

gas motion within the cylinder is one of the major factors that control the combustion process in spark ignition engine. it also has significant impact on heat transfer. both the bulk gas motion and the turbulence characteristics of the flow are important and governing the overall behavior of the flow. an arrangement for obtaining a stratified charge, using port injection, is proposed for a cur...