Al2O3 water in a Tube with Twisted Tape Inserts (Paper Validation), ANSYS Fluent

Paper Description

The present problem simulates the γ-Al₂O₃/water flow inside a circular tube with twisted tape inserts. The simulation is based on the reference article “Study on heat transfer and friction factor characteristics of γ-Al₂O₃/water through circular tube twisted tape inserts with different thicknesses“. Its results are compared and validated with the results in the article. In this project, the γ-Al₂O₃/water fluid will enter the computational domain with an initial temperature of 300K and a velocity of 0.716m/s (referring to Reynolds number = 500) through a multiple-staged twisted circular tube. The twisted tube’s outer wall is exposed to a heat flux rate of 5000 W/m2 and causes the fluid flow’s temperature to increase.

Twisted Tape Geometry & Mesh

The geometry of this project is designed in ANSYS design modeler and is meshed in ANSYS meshing software. The mesh type used for this geometry is structured, and the element number is 2146882.

γ-Al2O3/water Through a Circular Tube with Twisted Tape Inserts CFD Simulation Settings

The critical assumptions considered in this project are:

• Simulation is done using a pressure-based solver.
• The present simulation and its results are considered steady and do not change as a function of time.
• The effect of gravity has been taken into account and is equal to -9.81 in the Y direction.

The applied settings are summarized in the following table.

	Models
Viscous model		k-epsilon
	k-epsilon model	standard
	near-wall treatment	standard wall function
Energy		on
	Boundary conditions
Inlet		Velocity inlet
	Velocity magnitude	0.716 m/s
	Temperature	300 K
Outlet		Pressure outlet
Walls		Stationary wall
Outer Tube walls	Heat flux	5000 W/m2
Inner walls	Heat flux	0 W/m2
	Solution Methods
Pressure-velocity coupling		SIMPLE
Spatial discretization	Pressure	Second-order
	Momentum	first-order upwind
	Energy	first-order upwind
	turbulent kinetic energy	first-order upwind
	turbulent dissipation rate	first-order upwind
	Initialization
Initialization method		Standard
	Gauge pressure	0 Pa
	Velocity (x,y,z)	(0,0,0.716) m/s
	Turbulent kinetic energy	0.00192246 m2/s2
	Turbulent dissipation rate	0.03318268 m2/s3
	Temperature	300 K

Paper Validation Results

At the end of this simulation, the present work results are compared with results obtained by the paper. For this purpose, the diagram in figure 10 was used, which shows Nu number’s changes over different Re numbers. It should also be noted that we have validated the results for Re number = 500.

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