Abstract In this study, the stability dependence of turbulent Prandtl number ( $$Pr_t$$ P r t ) is quantified via a novel and simple analytical approach. Based on variance flux budget equations, hybrid length scale formulation fir...

The solar convection zone exhibits a strong level of differential rotation, whereby the rotation period of the polar regions is about 25-30% longer than the equatorial regions. The Coriolis force associated with these zonal flows perpetually “pumps” the convection zone fluid, and maintains a quasi-steady circulation, poleward near the surface. What is the influence of this meridional circulatio...

Improving the heat transfer performance of conventional fluid creates significant energy savings in process Industries. In this aspect, an experimental study was performed to evaluate Fe2O3-water (W)-engine oil (EO) nanofluid at different concentrations and hot inlet temperatures a plate exchanger. Experiments were conducted by mixing Fe2O3 nanoparticles (45 nm) W-EO mixture base with volume fr...

By using high molecular weight fluorescent passive tracers with different diffusion coefficients and by changing the fluid velocity we study the dependence of a characteristic mixing length on the Peclet number, Pe, which controls the mixing efficiency. The mixing length is found to be related to Pe by a power law, L(mix) proportional, variant Pe0.26+/-0.01, and increases faster than expected f...

Motion Control of Smart Material Based Actuators: Modeling, Controller Design and Experimental Evaluation Sining Liu, Ph.D. Concordia University, 2013 Smart material based actuators, such as piezoelectric, magnetostrictive, and shape memory alloy actuators, are known to exhibit hysteresis e ects. When the smart actuators are preceded with plants, such non-smooth nonlinearities usually lead to p...

Fully developed turbulent and laminar flows through symmetric planar and axisymmetric expansions with heat transfer were modeled using a finite-difference discretization of the boundary-layer equations. By using the boundary-layer equations to model separated flow in place of the Navier-Stokes equations, computational effort was reduced permitting turbulence modeling studies to be economically ...

the mixing behavior of the gas-liquid phase in three loop bioreactors was investigated. a gas-induced external airlift loop bioreactor (ealb), a forced-liquid vertical tubular loop bioreactor (vtlb) and a forced-liquid horizontal tubular loop bioreactor (htlb) were used for mixing studies as well as biomass production from natural gas. the effect of design parameters, riser to downcomer cross s...

The infinite Darcy-Prandtl number model is an effective reduced model for describing convection in a fluid-saturated porous medium. It is well known that the deterministic model does not possess a unique invariant measure. In this work we study the dynamics of the infinite Darcy-Prandtl number model, under an additive stochastic forcing of its low modes. This is the so-called stochastic infinit...

The article deals with numerical investigation of axisymmetric subsonic air to air ejector. An analysis of flow and mixing processes in cylindrical mixing chamber are made. Several modes with different velocity and ejection ratio are presented. The mixing processes are described and differences between flow in the initial region of mixing and the main region of mixing are described. The lengths...