Week 8 - Simulation of a backward facing step in OpenFOAM

Natural gas is one of the major combustion fuels used throughout the country. It is mainly used to generate industrial and utility electric power, produce industrial process steam and heat, and heat residential and commercial space. Natural gas consists of a high percentage of methane (generally above 85 percent) and varying…

PARAMETRIC STUDY ON GATE VALVE A gate valve controls the media’s flow by lifting the gate (open) and lowering the gate (closed). A gate valves distinct feature is the straight-through unobstructed passageway, which induces minimal pressure loss over the valve. Gate valves are used for applications where valve…

CYCLONE SEPARATOR Cyclone separators provide a method of removing particulate matter from air or other gas streams at low cost and low maintenance. Cyclones are somewhat more complicated in design than simple gravity settling systems, and their removal efficiency is much better than that of settling chamber. Cyclones are…

A conjugate heat transfer (CHT) corresponds with the combination of heat transfer in solids & heat transfer in fluids. In solids conduction dominates whereas in fluids convection dominates. In applications where working temperature is high, it is essential to calculated temperature distribution in solid to ensure it…

RAYLEIGH-TAYLOR INSTABILITY Aim: - To simulate the Rayleigh-Taylor instability in Ansys Fluent and state inferences based on grid-size and Atwood number.    As shown, a heavier fluid rests on a lighter fluid in a container. A horizontal interface separates the two fluids. Due to gravity the situation is unstable.…

INTRODUCTION Conjugate heat transfer involves a combination of heat transfer in solids and heat transfer in fluids. In solids conduction is dominant whereas in fluids convection. In most cases, heat transfer in solids is due to conduction. Fourier’s law of heat conduction defines the conductive heat flux proportional…

INTRODUCTION Ahmed body & its importance The flow past an automobile (cars, buses, trucks) under normal operating conditions is primarily turbulent. It has general characteristics of flow-separation, recirculation regions, wake flow, trailing vortices and interaction of boundary layer with vehicle. These phenomena…

The flow past a cylinder for intermediate range of Reynolds number has analytical solution which are elusive or do not exist. The results are based on experimentation and numerical schemes. The observed phenomena are discussed in brief from small to high Reynolds number. `Re = (rho*U_(infty)*d)/(mu)` Low Reynolds number…

INTRODUCTION The 'Tee' geometry or mixing Tee, is commonly employed where two fluid streams with different physical properties mix together, for example petroleum industry, HVAC systems. The effectiveness of mixing T can be defined in terms of uniformity of the properties at the outlet, for example temperature. The fluid…

The laminar flow through a pipe has viscous effects which affect the velocity and pressure distribution through the pipe. The flow is said to be fully developed when the axial velocity no longer varies along the length and is just a function of the radius of pipe. The flow is assumed to be purely axial, `u_z != 0`…

Second order derivatives appear in the Navier Stokes equations for viscous flows. To discretize second-order derivatives, the Taylor series can be used to determine the finite difference expressions. 1) Central differencing  In central differencing scheme, points left and to the right of the concerned point in the…

The laminar flow through a pipe is constrained by the walls and the viscous effects grow and meet and permeate the entire flow. The internal flow through a long duct shows there is an entrance region where an inviscid upstream flow converges and enters the tube. Viscous boundary layers grow downstream and retard the axial…

The flow over a backward facing step is common practical engineering occurence which is observed in internal flows in  turbines, diffusers, external flows over buildings or over stepped channels. These flows are characterized by flow separation and reattachment. For this case we consider a incompressible laminar-viscous…

1] The FVM is a numerical method for evaluating partial differential equations. Finite volume method uses the integral form      of the conservation law. The domain is divided into many control volumes and the conservation laws are approximated      on each of the control volumes. These terms…

The flow through a convergent divergent nozzle is assumed to be a steady, isentropic flow. At the inlet to the nozzle we have a reservoir, whose cross section area is very large. Hence the velocity at the inlet is very small, the properties at the inlet, pressure and temperature are stagnation properties. The flow expands…

UNSTEADY STATE ANALYSIS The unsteady 2d heat conduction equation is given by   `(delT)/(delt) = kappa*((del^2T)/(delx^2) + (del^2T)/(dely^2) )` It is a parabolic PDE, which lend themselves to marching solutions. By using forward-difference scheme for the time derivative and central-differencing scheme for spatial…