...Junfei Zhou; Xinjun Wang; Jun Li; Weitao Hou In order to further study the effects of the target channel shape on the cooling performance of the double swirl cooling (DSC), five double swirl channels formed by two overlapping elliptic cylinders with different length ratio between the vertical semi...

.... It demonstrates the first use of high-speed dual-plane orthogonally-polarized stereoscopic-particle image velocimetry (PIV) and synchronized OH planar laser-induced fluorescence in a premixed swirling flame. We use this technique to explore the effects of combustion and longitudinal acoustic forcing on the time...

... premixed prevaporizing-type swirl burner, equipped with a plain jet airblast atomizer, was investigated at various atomizing pressures and combustion air flow rates, using quarls from 0 deg to 60 deg in 15 deg steps. Both the 15 deg and the 30 deg quarls provided a 42% higher lean blowout stability...

... errors ( ê apr(r) ) are very low, which indicate that further refinement may not reduce the errors significantly. The maximum error is obtained at the R4 location in the runner, where the flow separation and the swirling effect are dominant and the selected SST model may not be sufficient to resolve...

... September 5, 2017; final manuscript received March 19, 2018; published online June 25, 2018. Assoc. Editor: Joseph Zelina. 05 09 2017 19 03 2018 Combustion Combustors Computational fluid dynamics Modeling Swirling Thermophysical Turbulence Turbulent Jet stirred reactors...

... was investigated. For this purpose, the geometry of the combustion chamber in the immediate vicinity to the inlet valve seats was modified. The geometrical modification measures were conducted iteratively by integrative determination of the swirl motion on a flow bench, by laser-optical methods and consecutively...

... by turbulence and bulk in-cylinder charge motion brought about by modulation of inlet port flow. This arrangement produces a load and speed adjustable amalgamation of swirl and counter-rotating tumble which provides the turbulence required to support stable low-temperature combustion. At higher load conditions...

.... The mechanisms of thermal energy transfer must be investigated by studying the flow characteristics and associated heat load. This paper experimentally investigates the effects of combustor operating conditions on the reacting flow in an optical single can combustor. The swirling flow was generated...

... seal for various inlet swirl ratios. Flow fields in the labyrinth seal with the eccentricity of the rotor are observed in detail and the detailed mechanisms that increase the destabilizing forces at high inlet swirl ratios are discussed based on the fluid governing equations associated with the flow...

... gets closer to the fan, yielding a smaller radius mean vortex near the fan. Signature features of the distortion device are observed in the velocity gradients, showing the wakes generated by the distortion screen vanes in the flow. The results obtained shed light onto the aerodynamics of swirling flows...

...Paul Jourdaine; Clément Mirat; Jean Caudal; Thierry Schuller The stabilization of premixed flames within a swirling flow produced by an axial-plus-tangential swirler is investigated in an atmospheric test rig. In this system, flames are stabilized aerodynamically away from the solid components...

...Sun Xiao-Lin; Wang Zhan-Xue; Zhou Li; Shi Jing-Wei; Cheng Wen Serpentine nozzles have been used in stealth fighters to increase their survivability. For real turbofan aero-engines, the existence of the double ducts (bypass and core flow), the tail cone, the struts, the lobed mixers, and the swirl...

... friction, as a result of the lower viscosity, the reduction of the oil film's axial velocity is less abrupt than previously observed at an oil temperature of T  = 30 °C. Hence, the oil film thickness is reduced and the liquid continues to travel axially along the journal surface in a swirling motion. When...

... Wisler. 26 07 2017 09 08 2017 Aeronautical propulsion Aerothermodynamics Combustion Combustors Computational fluid dynamics Engines Flame Fuel combustion Fuels Gas turbine technology Modeling Multiphase flows Sprays Swirling Turbulence Turbulent Two-phase Unsteady...

... states, modal dynamics, and flame-acoustic phase relations are evaluated. It is found that the unstable acoustic modes converge into a predominantly rotating character in the direction of the mean flow swirl. Furthermore, the flame modulation is observed to be in phase with the acoustic pressure at all...

...Alp Albayrak; Thomas Steinbacher; Thomas Komarek; Wolfgang Polifke Spectral distributions of the sound pressure level (SPL) observed in a premixed, swirl stabilized combustion test rig are scrutinized. Spectral peaks in the SPL for stable as well as unstable cases are interpreted with the help...

...Finn Lückoff; Moritz Sieber; Christian Oliver Paschereit; Kilian Oberleithner The precessing vortex core (PVC) represents a helical-shaped coherent flow structure typically occurring in both reacting and nonreacting swirling flows. Until now, the fundamental impact of the PVC on flame dynamics...

... a residence time of 200 ms. One concept for the combustion of NG and syngas mixtures comprises a generic swirl stage with a central lance injector for the syngas. The second concept includes a central swirl stage with an outer ring of jets. The combustion is analyzed for both concepts by OH*-chemiluminescence...

... dynamics Convection Engines Flame Modeling Swirling Thermoacoustics Unsteady flows Wave propagation Coupled behavior Combustion instabilities (CI) are a serious concern in the design process of aeronautical engines. They are still hard to predict and, as a consequence, generally appear...

...Kevin Prieur; Daniel Durox; Thierry Schuller; Sébastien Candel This article reports experiments carried out in the MICCA-spray combustor developed at EM2C laboratory. This system comprises 16 swirl spray injectors. Liquid n-heptane is injected by simplex atomizers. The combustion chamber is formed...