... to decompose the results. The computed flow fields were divided into four reconstructed parts, namely mean part, coherent part, transition part, and turbulent part. Then, the dynamic mode decomposition (DMD) algorithm was used to analyze the characteristics of the reconstructed fields. The results show...

... oscillations in Reynolds stress associated with the convection of periodic vortical structures. This result has important implications on hydrodynamic stability models and reduced-order computational fluid dynamics simulations, which do show the importance of turbulent transport on the problem, but do...

...J. A. Piehl; O. Samimi Abianeh; A. Goyal; L. Bravo Turbulent spray combustion of n -dodecane was modeled at relevant engine conditions using two combustion models (direct integration of chemistry (DIC) and flamelet generated manifolds (FGM)) and multifidelity turbulence models (dynamic structure...

.... The convective wall heat loss is modeled through introducing a source term in the conditionally filtered total enthalpy equation for the CMC cells adjacent to the wall. The mean heat flux is high on the middle surface of the bluff body, but relatively low near its edges. The turbulent heat flux based...

..., the instantaneous flame location can vary in thickness and location due to heat losses or imperfect mixing. Postflame phenomena (slow CO oxidation or thermal NO production) can be expected to be significantly influenced by turbulent eddy structures. Since typical gas turbine combustor calculations require insight...

... Gas turbine technology Thermoacoustics Turbulence Unsteady flows The multiscale nature of combustion dynamics and their coupling mechanisms makes the experimental investigation of the phenomena challenging. High thermal power density flames present in gas turbine combustors are naturally...

...), whereas the flow on the blade pressure side close to the band was accelerating (turbine) and directed toward the outlet. Flow separation from the blade leading edge created a vortical flow, which broke up into four parts as it traveled further downstream and created high-energy turbulent eddies...

... zone (TRZ). The Damkohler (Da) number in the reactor is the highest in the stabilization vortex; it varies from about Da ∼ 2 at ϕ = 0.55 to Da ∼ 0.2–0.3 at LBO conditions. Due to the reduced turbulent dissipation rate in PRZ, the Da number is an order of magnitude higher than in TRZ. The global blowout...

... motion results in a faster combustion, hence in a higher efficiency. In summary, the geometrical modifications close to the valve seat result in increased turbulence intensity. It was proven that this intensification raises the ratio of efficiency by 1.6%. 1 Corresponding author. Contributed...

... velocity profiles show that, as flow develops axially, the vortex present in the profile migrates clockwise, opposite to the rotation of the fan, and toward the spinner of the engine. The turbulent stresses indicate that the center of the vortex meanders around a preferred location, which tightens as flow...

...-adverse operations have made water-lubricated bearings increasingly popular. Due to different viscosity properties between oil and water, the low viscosity of water increases Reynolds numbers drastically and therefore makes water-lubricated bearings prone to turbulence effects. The turbulence model...

.... It is then shown that the axial velocity field produced by the axial-plus-tangential swirler is different from those produced by purely axial or radial devices. It takes here a W-shape profile with three local maxima and two minima. The mean turbulent flame front also takes this W-shape in an axial plane, with two...

... Français du Pétrole-Énergies nouvelles (IFPEN)). For discretization, the two-step Taylor–Galerkin ‘C’ scheme [ 28 ] is used, which is third-order accurate in space and time. Subgrid turbulence is modeled with the sigma model [ 29 ]. The computational domain comprises the last 90 mm of the upstream plenum...

... 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...

... the rotor leading edge and impinging on the pressure side as well as the turbulent boundary layer on the suction side represent significant noise sources. In the present investigation, the maximum in efficiency coincides with the minimum in noise emissions. The simulations are performed with the implicit...

... , J.-F. , Durox , D. , Schuller , T. , and Candel , S. , 2013 , “ Tomographic Reconstruction of Heat Release Rate Perturbations Induced by Helical Modes in Turbulent Swirl Flames ,” Exp. Fluids , 54 , p. 1498 . 10.1007/s00348-013-1498-2 [21] Bourgouin , J. , Durox , D...

... ), pp. 1 – 14 . 10.1007/BF02560457 [12] Zhang , Q. , Liu , H. , Ma , Z. , and Xiao , Z. , 2016 , “ Preferential Concentration of Heavy Particles in Compressible Isotropic Turbulence ,” Phys. Fluids , 28 ( 5 ), p. 055104 . 10.1063/1.4948810 [13] Hammitt , F. , Hwang...

... between the ignition probability field and the airflow turbulent kinetic energy and velocity fields. Local equivalence ratio enhances the importance of the ORZ. Once a successful ignition is accomplished on one injector, the injector-to-injector flame propagation must be examined. High-speed visualization...

...Andrew Marshall; Julia Lundrigan; Prabhakar Venkateswaran; Jerry Seitzman; Tim Lieuwen Fuel composition has a strong influence on the turbulent flame speed, even at very high turbulence intensities. An important implication of this result is that the turbulent flame speed cannot be extrapolated...

... and comparing it to experimental results. Large eddy simulation (LES) turbulence modeling is used to capture the flow physics that affects the inherently unsteady jet breakup phenomenon. The oil jet spreading width is the primary metric used for comparing the numerical and experimental results. The results...