Week 4: Project - Transient simulation of flow over a throttle body

Objective

• Setup and run transient state simulation for flow over a throttle body.
• Post processes the results and show pressure and velocity contours.
• Show the plots for pressure, velocity, mass flow rate and total cell count.
• Calculations on how you calculate the end time for the simulation.
• Create an animation in which it throttle movement should be visible

Step Up

Table1

Table2

Simulation Parameters

Simulation time parameter

Boundary Conditions

Elbow Conditions

Throtle Condition

Rotate center and Rotate about center of the throtle shaft

In geometry Dock- Measure-Driection-select Arc normal (select any three edges of the top face of the pin) to know the arc radius and arc normal which is pasted Throtle boundary conditions

Then the moment of the throtle is mentioned

Output files

Meshing

End time Calculation

Distance/lenght of the pipe =0.2 approx(adding x,y axis)

steady state velocity =222m/s

now velocity=distance/time

therefore t(time)=distance/velocity

t=0.2/222=9.009*e-4 approx-1e-3

i.e it takes 1e-3 sec complete the fluid flow inside the elbow

Pressure contours

2ms

4ms

8ms

From both the cases the inlet pressure is much higher than the outlet pressure Their is the restriction of the throtle at 25deg at 2ms and 50 deg at 4ms,so pressure at the throtle region increases

Velocity Contour

2ms

4ms

8ms

Their is sudden restriction of the throtle at 2ms and 4ms flow velocity decresease but as time proceeds (after 8ms) the fluid flows over the the throtle and the flow attains a higer velocity

Plots

Mass_flow_rate

Average velocity

Both the mass_flow_rate and the velocity oscilates from 0 to 8ms due to the movement of the throtle after 8ms steady output is reached that is mass_flow_rate is 0.066kg/s and velocity is 224m/s

Total_Cells

The cell count from zero to 8ms is not steady because of the varition of the meshing at the throtle (due to its movement from 0 to 8ms) after 8ms it comes to the original position therefore mesh would remain same all over the domain of the geometry ,so cells converges after 8ms

Static_Pressure

The pressure fluctuates from 0 to 8ms after that the inlet pressure converges

Animations

Moment of the throttle

Moment of the mesh with throttle

Velocity

Pressure

Conculsion

From the above observation we can conclude that there is fluctuation(0to8ms) in mass_flow_rate,avg_velocity,static pressure and total_cell_count due movement in the throtle,after 8ms sloution converges as the the throtle comes to the original position