We present a few-mode Galerkin model for convection in binary fluid layers subject to an approximation to realistic horizontal boundary conditions at positive separation ratios. The model exhibits convection patterns in form of rolls and squares. The stable squares at onset develop into stable rolls at higher thermal driving. In between, a regime of a so-called cross roll structure is found. Th...

the fluid flow and heat transfer in a three-dimensional microchannel filled with al2o3- water nanofluid is numerically investigated. the hybrid scheme is used to discretize the convection terms and simpler algorithm is adopted to couple the velocity and pressure field in the momentum equations. the thermal and flow fields were analyzed using different volume fractions of nanoparticles and diffe...

‎in this paper‎, ‎we have investigated the chaotic behavior of thermal convection in couple stress liquid saturated porous layer subject to gravity‎, ‎heated from below and cooled from above‎, ‎based on theory of dynamical system‎. ‎a low dimensional lorenz‎- ‎like model is obtained by using galerkin-truncation approximation‎. ‎we found that there is proportional relation between scaled couple ...

in this paper, the problem of turbulent forced convection flow of water- alumina nanofluid in a uniformly heated pipe has been thoroughly investigated. in numerical study, single and two-phase models have been used. in single-phase modeling of nanofluid, thermal and flow properties of nanofluid have been considered to be dependent on temperature and volume fraction. effects of volume fraction a...

in this paper, the nonlinear differential equation for the convection of the temperature distribution of a straight fin  with the thermal conductivity depends on the temperature is solved using adomian decomposition method and padé approximation(padm) for boundary problems. actual results are then compared with results obtained previously  using digital solution by runge–kuttamethod and a diffe...

We present an experimental study of turbulent convection in a cell with staggered fingers on its sidewall using water as the convecting fluid. Our measurements reveal that Nu , Ra20.27, and that the temperature probability density function (PDF) at the cell center is a double-peaked function which can be fitted by the superposition of two Gaussians. Moreover, it is found that the size of the lo...

Many molecular biology assays depend in some way on the polymerase chain reaction (PCR) to amplify an initially dilute target DNA sample to a detectable concentration level. But the design of conventional PCR thermocycling hardware, predominantly based on massive metal heating blocks whose temperature is regulated by thermoelectric heaters, severely limits the achievable reaction speed(1). Cons...

The Rayleigh-Bénard theory by Grossmann and Lohse [J. Fluid Mech. 407, 27 (2000)] is extended towards very large Prandtl numbers Pr. The Nusselt number Nu is found here to be independent of Pr. However, for fixed Rayleigh numbers Ra a maximum in the Nu(Pr) dependence is predicted. We moreover offer the full functional dependences of Nu(Ra,Pr) and Re(Ra,Pr) within this extended theory, rather th...

In this paper, we present experimental results on the interplay between two different symmetry breaking mechanisms in a pattern forming system, namely inclined layer convection (ILC) with a spatially modulated heated plate. By varying the relative strength and relative orientation, we explored in detail the interplay of these symmetry breaking mechanisms. We found a stabilization of spatio-temp...