Heater Applied for a Room HVAC, CFD Simulation

Description

Project Description

The present problem simulates heat transfer by a radiator inside a room. In fact, the heater is connected to one of the sidewalls of the room, which acts as a heat source, and its body has a constant thermal flux equal to 1886.792 W.m-2. The sidewalls and ceiling have a thickness of 0.2 m of wood, which has convection heat transfer with the outside; Thus, the ambient air temperature is assumed to be 280 K and the convection coefficient is assumed to be 10 W.m-2.K-1. The purpose of this study is to investigate the heat transfer rate from the heater to the interior of the room using natural convection and buoyancy effect. Therefore, the gravity force is applied to the model.

Room and Heater Geometry & Mesh

We carry out the present 3-D model using the Design Modeler software. The present model consists of a room in the shape of a rectangular cube with dimensions of 4 m * 3 m * 3 m and a heater in the shape of a rectangular cube with dimensions of 0.1 m * 0.8 m * 0.5 m in its interior which is connected to one of the room’s sidewalls. The figure below shows the geometry.

The meshing of room and the heater is done using ANSYS Meshing software and the mesh type is structured. The element number is 87865. The figure below shows the mesh.

Room HVAC by a Heater CFD Simulation

To simulate the present model, several assumptions are considered:

• We perform a pressure-based solver.
• The simulation is steady
• The gravity effect on the fluid is equal to -9.81 m.s-2 along the z-axis.

A summary of the defining steps of the problem and its solution is given in the following table:

(heater)	Models
Viscous model			k-epsilon
	k-epsilon model		standard
	near-wall treatment		standard wall function
Energy			on
(heater)	Boundary conditions
Heater			wall
	wall motion		stationary wall
	heat flux		1886.792 W.m-2
Sidewalls & roof			wall
	wall motion		stationary wall
(heater)	convection	heat transfer coefficient	10 W.m-2.K-1
		free stream temperature	280 K
Ground			wall
	wall motion		stationary wall
	heat flux		0 W.m-2
(heater)	Solution Methods
Pressure-velocity coupling			Coupled
Spatial discretization	pressure		second-order
	momentum		second-order upwind
	turbulent kinetic energy		second-order upwind
	turbulent dissipation rate		second-order upwind
	density		second-order upwind
	energy		second-order upwind
(heater)	Initialization
Initialization method			Standard
	gauge pressure		0 Pascal
	velocity (x,y,z)		0 m.s-1
	temperature		280 K

Results:

At the end of the solution process, the velocity, temperature, and pressure contours, pathlines, and velocity vectors all in two-dimensional and three-dimensional, are obtained.

 

All files, including Geometry, Mesh, Case & Data, are available in Simulation File. By the way, Training File presents how to solve the problem and extract all desired results.

This ANSYS Fluent project includes CFD simulation files and a training movie.