Sloshing of a Tanker Truck CFD Simulation, Ansys Fluent Training

Sloshing of a Tanker Project Description

In this project, Ansys Fluent software has been used to simulate the sloshing of a tanker truck. The Volume of  Fluid (VOF) model has been used to simulate and solve the two-phase flow field equations. The primary phase is air and, the secondary phase is water. The truck brakes at the speed of 15 m/s, and after 3 seconds, it stops. This means that in addition to gravity acceleration, the water inside the tanker feels the brake deceleration.

Geometry & Mesh

The geometry of the present model is generated using SpaceClaim software. The tanker dimension is 12300* 1900.1867 mm.

The meshing of the present model has been done using Ansys Meshing software. The mesh type is structured in all of the computational domains, and the cell number is equal to 233,700.

Sloshing of a Tanker CFD Simulation Settings:

We consider several assumptions to simulate the present model:

1. Due to the incompressibility of the flow, the pressure-based solver method has been selected.
2. The simulation is transient.
3. The gravity effect is considered equal to -9.81 m.s^-2 on Y-axis
4. The brake deceleration is considered at the first 3 seconds equal to 5 m.s^-2 on X-axis

The K-epsilon Realizable viscous model with Scalable wall function has been used to solve the turbulent flow equations. The pressure-velocity coupling scheme is SIMPLE. The second-order upwind discretization method has been used for Momentum, Turbulent kinetic energy, and Turbulent dissipation rate.

The following table represents a summary of the defining steps of the problem in this project and its solution:

General
Solver	Type	Pressure-based
	Time	Transient
Gravity	X	IF(t<=3[s],5[m/s^2],0[m/s^2])
	Y	-9.81 [m/s^2]
	Z	0
Models
Multiphase
	Model	Volume of Fluid
	Number of Eulerian phases	2(air & water)
	Interface modeling	Sharp
	Formulation	Explicit
	Primary phase	air
	Secondary phase	water
Phase interaction
	Surface Tension coefficient[N/m]	Constant = 0.072
Viscous
	k-epsilon	Realizable
	Near wall treatment	Scalable wall functions
Material Properties
Air
	Density	1.225
	viscosity	1.7894e-05
water-liquid
	Density	998.2
	viscosity	0.001003
Methods
Pressure-Velocity Coupling		SIMPLE
	Pressure	PRESTO
	Momentum	Second-order upwind
	Turbulent kinetic energy	Second-order upwind
	Turbulent dissipation rate	Second-order upwind
	Volume fraction	Compressive
Initialization
Initialization methods		Standard
Patch	Phase	water
	Variable	Volume Fraction
	Zones to patch	Water_mesh_
	Value	1
Run calculation
Time step size		0.002
Max iterations/time step		20
Number of time steps		5000

Sloshing of a Tanker Results

After the solution process is completed, contours of velocity, Pressure, Water volume fraction, Eddy viscosity, Streamline, and Turbulence intensity are extracted. As can be seen, under the influence of gravity and deceleration, the water inside the truck tanker moves and hits the front wall of the tanker. After 3 seconds, the truck stops, and, since that time, only gravity affects the water.