Whether or not a chemical reaction in a fluid leads to an explosion is shown to depend on four timescales: that for the chemical reaction to heat up the fluid containing the reactants and products, for heat conduction out of the reactor, for natural convection in the fluid, and finally for chemical reaction. This approach is developed for an irreversible, n-th order chemical reaction, A → B occ...

This paper presents a study of the dual reciprocity boundary element method (DRBEM) for the laminar heat convection problem between two coaxial cylinders with constant heat flux boundary condition. DRBEM is one of the most successful technique used to transform the domain integrals arising from the nonhomogeneous term of the Poisson equation into equivalent boundary only integrals. This recentl...

The present study carries out numerical analysis of the coupled natural convection and oxygen transfer of low-Prandtl-number ( 0.02) liquid lead and lead–bismuth eutectic (LBE) for testing and calibrating low concentration level oxygen sensors. The analysis is performed on the two-dimensional coordinates in a rectangular container, where the fluid movement is laminar for the purpose of sensor t...

Laminar natural convection in a trapezoidal cavity filled with various fluids is studied numerically using a finite volume method. The cavity inclined left and right sidewalls are maintained at constant cold temperature while the top wall is maintained at constant hot temperature. The bottom wall is considered adiabatic. Fluid flow fields , isotherm patterns and the average Nusselt number are p...

A new way of ascertaining whether or not a reacting mixture will explode uses just three timescales: that for chemical reaction to heat up the fluid containing the reactants and products, the timescale for heat conduction out of the reactor, and the timescale for natural convection in the fluid. This approach is developed for an n-th order chemical reaction, A → B occurring exothermically in a ...

This work presents the application of density-based topology optimisation to the design of three-dimensional heat sinks cooled by natural convection. The governing equations are the steady-state incompressible Navier-Stokes equations coupled to the thermal convection-diffusion equation through the Bousinessq approximation. The fully coupled non-linear multiphysics system is solved using stabili...

A model for steady laminar natural convection inside vertical, arbitrarily shaped isothermal ducts of constant cross section is presented. The model is based on a combination of asymptotic solutions for fully developed and developing, boundary-layer  ow. The fully developed asymptote model utilizes forced convection, internal  ow modeling techniques, and an approximate model is presented, whi...

2-D laminar flow with natural Convection with different checker board removing approaches (staggered and collocated grid systems) is solved to provide comparison between staggered and collocated arrangements. SIMPLEC algorithm is employed for pressure velocity coupling. The results are first presented for a benchmark problem and then the effect of the inclination angle and aspect ratio are inve...

The FORTRAN CFD code 3DINAMICS has been developed to simulate momentum, mass, and heat transfer in laminar and turbulent unsteady three-dimensional flows. The code has been successfully applied to the simulation of several engineering flows, particularly we present four different ones: lid-driven cavity, natural convection in a cubical cavity, hydrodynamics in shallow ponds and three-dimensiona...

2014 The determination of temperature profiles in gases is based on the light beam deflection due to the refractive index gradient induced by a temperature gradient at constant pressure. The geometry considered for the system is a cylinder of arbitrary section characterized by isothermal generative lines. A parameter estimation method and a parabolical trajectory method are considered to treat ...