2014 The threshold of the transition to turbulence of low Prandtl number convective flows occurs much closer to the convective threshold in an extended cylindrical cell, than one could infer from a straight roll stability analysis. Convection then involves non local effects together with a closure of the spatial scales. We solve these problems by constructing an explicit analytical solution of ...

The non-orthogonal boundary-fitted coordinate transformation method is applied to the solution of steady three-dimensional momentum and energy equations in laminar flow to obtain temperature field and Nusselt numbers in the thermal entry region of straight ducts of different cross sectional geometries. The conservation equations originally written in Cartesian coordinates are parabolized in the...

An inertial navigation system (INS) complete with extended Kalman filters (EKFs) to mitigate sensor measurement errors is described in this paper for a six-degree-of-freedom (6-DOF) pectoral fin propelled unmanned underwater vehicle (UUV). Simulation results are discussed and the vehicle model is validated with initial experimental data. After modeling the sensor performance characteristics, EK...

a micro-channel heat exchanger reactor with different micro-baffle shapes has been studied numerically. governing equations were solved base on the finite volume method with fluent software. in upper section, oxidation reaction of methanol was occurred and in lower section, steam reforming of methanol was done. two sections were separated with solid part which played as heat exchanger and trans...

Lebiasina ardilai is described from the upper Mazaruni in Guyana. The new species differs from all its congeners by its color pattern consisting of: a narrow, nearly straight primary stripe, extending from posterior to humeral blotch to near the vertical through anal-fin origin, being absent or inconspicuous in females and conspicuously marked in males; the presence of four series of dark blotc...

a lattice boltzmann method is applied to demonstrate the comparison results of simulating natural convection in an open end cavity using different hydrodynamic and thermal boundary conditions. the prandtl number in the present simulation is 0.71, rayleigh numbers are 104,105 and 106 and viscosities are selected 0.02 and 0.05. on-grid bounce-back method with first-order accuracy and non-slip met...

Plate fin-tube heat exchangers are widely used in air conditioning and refrigeration systems other industry fields. Various errors made the manufacturing process can result formation of an gap between tube fin. Several numerical simulations were carried out for a symmetric section plate exchanger to study influence on transfer under periodic flow conditions. Different locations sizes spanning 1...

Paraffin-based latent heat storage has a higher thermal capacity than sensible storage. Despite that, the actual implementation of paraffin as an active (ALHS) system is limited due to low charging and discharging rate with unequal temperature distribution impact mushy region formation. The present study evaluates finned-coil exchanger for ALHS tank overcome related problems. Three configuratio...

A Lattice Boltzmann method is applied to demonstrate the comparison results of simulating natural convection in an open end cavity using different hydrodynamic and thermal boundary conditions. The Prandtl number in the present simulation is 0.71, Rayleigh numbers are 104,105 and 106 and viscosities are selected 0.02 and 0.05. On-Grid bounce-back method with first-order accuracy and non-slip met...