Energy dissipation rate, ε, is an important parameter for nearly every experiment on turbulent flow. Mathematically precise relationships between ε and other measurable statistics for the case of anisotropic turbulence are useful to experimentalists. Such relationships are obtained for which the measurable statistics are the 3rd-order and 2nd-order velocity structure functions as well as the ac...

A jet of fluid discharging into a cross stream, also known as Jet In Crossflow (JICF), has received many experimental and numerical investigations. In addition to the fundamental understanding of threedimensional mixing and shear flow characteristics, the fluid dynamics research community often regarded it as a benchmark test case for validating turbulence models. Although many authors consider...

Roughness elements or turbulence promoters have been widely used to enhance heat transfer in cooling passages of modern gas turbine blades. Although such ribs substantially enhance heat transfer, the heat transfer coefficient is reduced immediately at corner downstream of each rib, creating hot spots. To remove such hot spots some of the ribs can be detached from the channel walls. In this pape...

Ultrasonic technology and response surface methodology (RSM) wereused for optimization of extraction of condensed tannins from the leaf, acron, gland and gall of oak. Three independent variables such as solvent percentage (%), temperature (°C) and time (min) were studied. Effect of methanol concentration was found to be significant on all responses. Optimal ultrasonicassisted extraction (UAE) c...

in this paper, convection heat transfer of al2o3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. for each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. the governing equations in steady state and axisymme...

It is experimentally shown that the nonclassical high Reynolds number energy dissipation behavior, C(ε)≡εL/u(3)=f(Re(M))/Re(L), observed during the decay of fractal square grid-generated turbulence (where Re(M) is a global inlet Reynolds number and Re(L) is a local turbulence Reynolds number) is also manifested in decaying turbulence originating from various regular grids. For sufficiently high...

A pressure-based implicit procedure to solve the Euler and Navier-Stokes equations on a nonorthogonal mesh with collocated finite volume formulation is described. The boundedness criteria for this procedure are determined from Normalized Variable diagram (NVD) scheme.The procedure incorporates the ε−k eddy-viscosity turbulence model. The algorithm is tested for inviscid and turbulent transonic ...

The numerical results of mathematical modeling a two-phase, axisymmetric swirling turbulent flow in the separation zone centrifugal separator are presented. movement carrier gas was modeled using RANS, which were closed SARC turbulence models, SST-RC model, and SSG/LRR-RSM-w2012 model. For solution problem, SIMPLE algorithm used. article compares calculation models. comparison calculations with...

It is shown that, for stationary isotropic turbulence, Taylor’s well known dissipation surrogate Du/L can be derived directly from the Karman-Howarth equation and is in fact a surrogate for inertial transfer, which becomes equal to the dissipation, as the Reynolds number tends to infinity. The expression found for the dissipation rate ε is ε = A3u ′3 L [