There are many approaches to determine the sound propagated from turbulent flows.  In hybrid methods, the turbulent noise source field is computed or modeled separately from the far-field calculations.  To have an initial and quick estimation of the sound propagation, less computationally intensive methods can be developed using stochastic models of the turbulent fluctuations.   In this paper, ...

The current study presents the results of the aerodynamic noise prediction of the flow field around a NACA 0012 airfoil at a chord-based Reynolds number of 100,000 and at 8.4 degree angle of attack. An incompressible Large Eddy Simulation (LES) turbulence model is applied to obtain the instantaneous turbulent flow field. The noise prediction is performed by the Ffowcs Williams and Hawkings (FW-...

the design and optimization of hydrocyclones using cfd techniques are gaining popularity and the key to a successful simulation lies with the accurate description of the high turbulent swirling behavior of the flow. this paper presents a detailed comparison between the omega rsm and the rng k–e turbulence model, which are both derived specially for modeling swirling or rotational flow, in the s...

in this study, the dispersion mechanisms of aerosols suspended in a turbulent plane channel flow is investigated using a novel numerical approach. a turbulent channel flow is simulated by a direct numerical simulation (dns) method, for which no-slip boundary conditions are assumed at the top and bottom walls, while periodicity conditions are applied on the other sides. dns, in particular, allow...

the current study presents the results of the aerodynamic noise prediction of the flow field around a naca 0012 airfoil at a chord-based reynolds number of 100,000 and at 8.4 degree angle of attack. an incompressible large eddy simulation (les) turbulence model is applied to obtain the instantaneous turbulent flow field. the noise prediction is performed by the ffowcs williams and hawkings (fw-...

We consider the effects of distributed roughness on the boundary-layer transition over a rotating disk using both theoretical and experimental approaches. The theoretical approach further develops Yoon et al.’s method [Int. J. Heat Fluid Flow, 28, p262 (2007)] for obtaining the steady-flow solutions for a general surface distribution function. Full threedimentional stability analyses are conduc...

In this study, the thermal characteristics of turbulent nanofluid flow in a helical tube in the tube heat exchanger (HTTHE) were assessed numerically through computational fluid dynamics (CFD) simulation. The findings of both the turbulent models: realizable k-epsion (k-ε) and re-normalisation group (RNG) k-epsilon were compared. The temperature distribution contours show that realizable and RN...

To simulate the effect of free st ream turbulence on turbulent spot formation, experiments were conducted on the interaction of localized three-dimensional disturbances with the harmonic waves in a laminar boundary layer on a flat plate. Experiments conducted in three-dimensional diverging flow (but zero pressure gradient) show, while individually the disturbances decay downstream, their intera...

mixed convection is a fundamentally significant heat transfer mechanism that occurs in selection industrial and technological applications. in this study, first the laminar mixed convection inside rectangular enclosure with moving wall and aspect ratio=10 is modeled and then the results are compared with other investigate. after showing varity of results, the investigation is continued with tur...

In this study, turbulent compressible gas flow in a rectangular micro-channel is numerically investigated. The gas flow assumed to be in the subsonic regime up to Mach number about 0.7. Five low and high Reynolds number RANS turbulence models are used for modeling the turbulent flow. Two types of mesh are generated depending on the employed turbulence model. The computations are performed for R...