The present work is an attempt to model, analyze, and control the flow at the base of an abruptly expanded circular duct by using design of experiments (DOE) and response surface methodology (RSM). Tiny-jets in the form of orifice were positioned at an interval of 900, 6.5 mm from the primary axis of the main jet of the nozzle. Experiments were conducted to measure two responses namely, base pr...

Vitiation air heater (VAH) combustion characteristics for a direct-connect scramjet combustor (DCSC) were experimentally studied. The VAH consists of head, modular chamber, and circular-to-rectangular shape transition (CRST) nozzle. CRST nozzle transforms the circular cross-sectioned rocket-type into rectangular combustor. exit Mach numbers at top, middle, bottom measured using tungsten wedge. ...

This paper presents asymptotically stable schemes for patching of nonoverlapping subdomains when approximating the compressible Navier–Stokes equations given on conservation form. The scheme is a natural extension of a previously proposed scheme for enforcing open boundary conditions and as a result the patching of subdomains is local in space. The scheme is studied in detail for Burgers’s equa...

Cavitation and turbulence in a diesel injector nozzle has a great effect on the development and primary breakup of spray. However, the mechanism of the cavitation flow inside the nozzle and its influence on spray characteristics have not been clearly known yet because of the internal nozzle flow complexities. In this paper, a comprehensive numerical simulation is carried out to study the intern...

The use of impinging liquid jets in electronics thermal management is attracting some consideration due to their very high heat transfer coefficients, hot spot targeting capabilities and moderate hydraulic power requirements. In this investigation an experimental study of the cooling capabilities of impinging water jet arrays is presented. Of particular interest here is the influence that the i...

Methods of modifying the water distribution pattern of an impact-drive sprinkler are described. A method of pattern modification called intermittent diffusion is introduced. A deflector attached to the drive arm intermittently diffuses the jet of a standard circular-orifice nozzle, producing desirable pattern shapes while maintaining a large pattern radius. Uniformity of application for both wi...

The current study addresses the effect of different designs exhaust mixer and aft-deck on performance a two-dimensional convergent nozzle represented by internal external flows heat transfer process. cone angles 10°, 15°, 20°, lengths 140 mm, 280 420 mm was investigated. To address an aft-deck, flow behavior with compared to that without aft-deck. Then, aft-decks rectangular trapezoid shapes re...

The lag model proposed by Olsen and Coakley is incorporated into the baseline two-equation k-ω turbulence model to simulate the transonic and supersonic turbulent separated flow. The performances of the lagged k-ω turbulence model is assessed by computing two transonic airfoil flow cases, the RAE2822 Case 10 and the 18% thick double circular arc airfoil, and a separated nozzle flow. The computa...

In order to improve the cavitation performance of self-excited oscillation nozzle (SEON), a novel SEON with circular arc curve chamber was designed by changing wall profile SEON. The studied numerically. Taking vapor volume distribution and fraction as evaluation indexes, influences on were analyzed. addition, it compared broken-line numerical results show that is first enhanced then weakened i...