This study aims to derive valuable insights for utilizing Computational Fluid Dynamics (CFD) based on Reynolds-Averaged Navier–Stokes (RANS) and Detached Eddy Simulation (DES) turbulence models (TMs) analyze a specific radial ejector configuration known as the Variable Geometry Radial Ejector (VGRE). The VGRE features primary nozzle duct plates with adjustable disk-like surfaces, allowing changes in throat areas within single ejector. Extensive numerical investigations of are conducted by...

This work focuses on improving ejector performance in variable conditions by developing a radial flow geometry (VGRE). The research objective was to demonstrate the of improved VGRE, which can operate more effectively under changing operating compared fixed design. VGRE developed and experimentally tested enable adjustment nozzle throat areas suit different various applications. Radial ejectors have smaller size than axial ejectors, is significant advantage some Results showed that achieved...

Simulation of internal combustion engine heat transfer using low-dimensional thermodynamic modeling often relies on quasisteady correlations. However, unsteady thermal boundary layer could make a useful contribution because the inherent unsteadiness environment. Previous formulations energy equations for appear to imply that it is necessary adopt restrictive assumption isentropic processes occur in gas external layer. Such restrictions are not required and we have investigated if can improve...

A coupled numerical-experimental investigation studying the applicability of a Sliding Doors variable geometry inlet starting mechanism for 2D SCRAMjet at Mach 6 has been undertaken. Door opening speeds ranging from 3 to 20ms repeatedly produced started conditions when tested within TUSQ Low-Enthalpy Wind Tunnel. Transient flow during door retraction was captured both quantitatively and qualitatively via surface pressure measurements Schlieren visualization techniques. blunt wedge protruding...

The vertical gravitational flash tank separator can be used to increase the performance of a refrigeration cycle. Using improves effective area and enhances heat transfer coefficient inside evaporator. However, still needs further investigation improve its performance. This paper provides an study demonstrate improvement separation efficiency using extractor separator. Computational Fluid Dynamic (CFD) was assess optimum configuration dimension extractor. A series experiments were performed...

Arcjet facilities have been used extensively for ablation and materials characterization but arcjets do not correctly simulate the hypervelocity flow during reentry. Impulse can aspects of reentry flows, cannot duplicate extended-duration thermal environments. To address such deficiencies in short-duration testing environments, a novel plasma technique preheating axisymmetric samples heat-shield has developed. The heating demonstrated using blow-down arrangement at University Southern...

To optimize a vertical flash tank separator, the characteristics of flow entering separator are required to be known. A improves performance refrigeration cycle by separating liquid from liquid-gas and providing evaporator with only refrigerant. This technique effective area enhances heat transfer coefficient in evaporator. paper investigates influence inlet operating conditions an expansion device, on adiabatic two-phase development horizontal pipe downstream device. work also compares...

To achieve higher performance from ejectors at some working conditions, implementations of variable geometry might be possible.While axisymmetric with axial flow paths have limitations that make practical implementation difficult, radial ejector configurations a path is conducive to changes in nozzle and throat area during operation.The geometric adjustment the could made by simply changing separation duct walls and/or order optimize over range different conditions.The effects such on been...

Simulation of internal combustion engine heat transfer using low-dimensional thermodynamic modelling often relies on quasi-steady correlations. However, unsteady thermal boundary layer could make a useful contribution because the inherent unsteadiness environment. Previous formulations energy equations for appear to imply that it is necessary adopt restrictive assumption isentropic processes occur in gas external layer. Such restrictions are not required and we have investigated if can...

improved VGRE, which can operate more effectively under changing operating conditions compared to a fixed geometry design. The VGRE was developed and experimentally tested enable adjustment of the nozzle ejector throat areas suit different in various applications. Results showed that achieved higher entrainment ratio critical compression design optimal performance obtained with duct separations 0.5 mm 3.0 mm, respectively. results also indicated wall static pressure region similar observed...

Two types of variable compression ratio engine are considered: i) a continuously (VCR) device that optimises efficiency at all loads, and ii) VCR allows the to operate one two discrete ratios. The simulated configuration uses late intake valve closing (LIVC). A maximum geometric (GCR) 17:1 is adopted in simulations resulting constant effective 10.2:1 configurations. Reduction from full load achieved simulation with LIVC until GCR reached after which lower loads through throttling. In...