In recent years attention of researchers has been focused on the combustion generated particles in order to have a deeper knowledge on their formation and develop combustion systems with higher efficiency and lower environmental impact [1,2]. Opposed-flow configuration allows to study behavior and sooting tendency of fuels, avoiding fluidodynamic problems fundable in diffusion flames laminar or...

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...

– Networks of caustics can occur in the distribution of particles suspended in a randomly moving gas. These can facilitate coagulation of particles by bringing them into close proximity, even in cases where the trajectories do not coalesce. The long-time morphology of these caustic patterns depends upon the Lyapunov exponents λ1, λ2 of the suspended particles, as well as the rate J at which par...

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...

the reaction of ch3o2 radicals with acetaldehyde on the solid surface of nh4no3 has been studied in a flow capillary reactor at low pressure and room temperature. the experiments were performed using epr spectrometer combined with the kinetic method of radicals freezing. peroxy radicals revealed an oscillation complex behavior during the process regarding to the phenomenon of radicals multiplic...

Turbulent wake of wind turbine will reduce the power output of wind farm. The access to real turbulent wake of wind turbine blades with different spatial and temporal scales is provided by the pulsed Coherent Doppler Lidar (CDL) which operates by transmitting a laser beam and detecting the radiation backscattered by atmospheric aerosol particles. In this paper, the authors discuss the possibili...

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...

the energy equation for turbulent flow of fiber suspensions was derived in terms of second order correlation tensors. fiber motion of turbulent energy including the correlation between pressure fluctuations and velocity fluctuations was discussed at two points of flow field, at which the correlation tensors were the functions of space coordinates, distance between two points, and time.