Cooling of an Airfoil Surface by Lateral Air Inlets, CFD Simulation

Description

Introduction

In addition to aircraft wings, airfoil properties are of great importance in engineering and scientific applications in aircraft and ships, helicopters, compressors, turbines, fans, pumps, wind tunnels, hydraulic ducts and mills, and many other issues and industries. Most of the issues with airfoils are related to aircraft wings. Another important application is the use of airfoil in turbine blades and is related to turbine and jet engines. It should be noted that the calculation and analysis of turbine airfoils due to their more complex shape is much more complex and difficult than the analysis of aircraft wings. In the field of jet engines, surface cooling of airfoils has become one of the most important issues in mechanical engineering as well as aerospace.

Airfoil Surface Cooling Project description

In this project, the movement of heated airflow over the surface of an airfoil and the surface cooling of the mentioned airfoil by the means of lateral air inlets is simulated. The heated air enters the computational domain with velocity and temperature of 15 m/s in the X direction and 600 K respectively. Two lateral air inlets are responsible for the surface cooling of the blade or airfoil. The air also enters through these cooling inlets with velocity and temperature of 6.59 m/s and 300 K. Standard k-epsilon model is exploited to solve turbulent flow equations and the Energy equation is activated to calculate the temperature distribution inside the computational domain.

Geometry and mesh

The geometry of this project is designed in ANSYS design modeler and meshed in ANSYS meshing. The mesh type used for this geometry is unstructured and the element number is 582263.

Airfoil Cooling CFD simulation settings

The key assumptions considered in this project are:

• Simulation is done using pressure-based solver.
• The present simulation and its results are considered to be steady and do not change as a function time.
• The effect of gravity is neglected.

The applied settings are summarized in the following table.

(Cooling)	Models
Viscous model		k-epsilon
	k-epsilon model	Standard
	near wall treatment	standard wall function
Energy		On
(Cooling)	Boundary conditions
Inlets		Velocity inlet
Inlet	Velocity	15 m/s
	Temperature	600 K
Jet inlets	Velocity	6.59 m/s
	Temperature	300 K
Outlet		Pressure outlet
	Gauge pressure	0 Pa
Walls		Stationary wall
	Heat flux	0 W/m2
(Cooling)	Solution Methods
Pressure-velocity coupling		SIMPLE
Spatial discretization	Pressure	PRESTO!
	Momentum	QUICK
	Energy	QUICK
	turbulent kinetic energy	QUICK
	turbulent dissipation rate	QUICK
(Cooling)	Initialization
Initialization method		Standard
	Pressure	0 Pa
	Velocity (x,y,z)	(15,0,0) m/s
	Temperature	600 K
	turbulent kinetic energy	0.135
	turbulent dissipation rate	11.22894

Airfoil Cooling Results & discussion

As can be observed in temperature contour and changes of blade temperature in terms of blade position diagram, the lateral inlets have effectively done their job and lowered the temperature of the blade’s surface, as the free stream has a temperature of 600 K and the blade’s final temperature is less than 520 K.

Mesh file is available in this product. By the way, the Training File presents how to solve the problem and extract all desired results.