Modelling and simulation of flow through a flowbench
Aim:
To model the flowbench in solidworks and to made simulation on the modelled flowbench using solid works.
Objectives:
- To model flowbench with valve parameter.
- To made a grid dependence test.
- To find out the best grid at a particular valve lift.
- To made the parametric study to analyse the mass flow rate on different valve lift.
Flowbench:
Flowbench is device that is used to analyse the aerodynamic qualities of the fluid that entering into the engine or any other devices. In engines, the amount of fluid passed in to the cylinder plays a pivotal role. The intake and the exhaust port of the ic engine was analysed by using the flowbench apparatus. In that simulation the flowbench is considered as the intake and exhaust port and the simulation is done with the respective fluid. By using this flowbench apparatus, we can analyse the nature of the fluid and the changes in the model due to the flow of that fluid.
Modelling of flowbench:
- Initially, the base cylinder is made with the diameter of 0.05m and length of 0.1m.
- The inlet manifold is modelled by creating the rough sketch and made a plane at the end.
- The inlet manifold is made with the diameter of 0.025m.
- The circle is sweep to get the inlet manifold.
- To create the valve, a plane is made at the tail end of the inlet valve.
- The valve is drawn with the suitable dimensions and constraints so that the valve opening can be changed.
- Finally, shell tool is used for obtaining the actual hollow flow bench.
Simulation setup:
- The two lids are formed at the inlet face and at the bottom of the cylinder.
- The fluid is assigned as air.
- The boundary conditions are assigned with total pressure at the inlet lid with the value of 101325 Pa.
- Another boundary condition of static pressure is assigned at the bottom lid of the cylinder with the value of 40662.5 Pa.
- The surface goal is assigned at the bottom lid of the cylinder to analyse the mass flow rate.
- The refined mesh is applied.
- The local mesh is reffined at the surroundings of the valve.
Grid dependence test:
The grid dependence test is made with three different mesh values of 3,4 and 5 at the automatic mesh generator. The valve is opened with 0.001m. The velocity plot obtained on the three cases was analysed and the best one in figured out.
Velocity plot:
Mesh 3:
Mesh 4:
Mesh 5:
Based on the velocity plot obtained, the best grid value can be found. The velocity plot of the mesh with the value 5 is more fine and clear when compared it with the other two plots. The velocity flow of the assigned fluid is clearly demonstrated at the grid size 5. It explains that greater the grid size finer will be results. So the best size is obtained as mesh 5.
Parametric study:
- The dimension value is assigned between the upper surface of the lift and the boundary of the cylinder.
- By keeping the smart dimension option ON, the new parametric study is opened and the dimension parameter of the valve opening dimension is assigned.
- The intial value and the end value is assigned along with the step value.
- By initializing these parameters, the valve can be opened automatically during simulation.
- The automatic mesh value is assigned as 5.
- The velocity cut plot, pressure cut plot and the flow trajectories are obtained as the output.
- The initial lift value is assigned as 0.001m and the end value is assigned as 0.008m and the step value is assigned as 7.
- The 7 valve lift values are obtained as 0.001,0.00216,0.0033,0.0045,0.0056,0.00683 and 0.008m.
Results and discussions:
The mass flow rate values, velocity plot, pressure plot and the flow trajectories for all the 7 valve lift values are obtained.
Velocity plots:
Valve lift 0.001m:
Valve lift 0.00216m:
Valve lift 0.0033m:
Valve lift 0.0045m:
Valve lift 0.0056m:
Valve lift 0.00683m:
Valve lift 0.008m:
The maximum velocity region is increased with increasing the valve lift. At the small opening of valve, there is minimum flow of the fluid inside the cylinder. Thus the region with maximum velocity is low. But when the valve lift value is increased to the maximum value of 0.008m, the flow of fluid inside the cylinder is maximum. Thus the maximum velocity region is high.
Pressure plot:
Valve lift 0.001m:
Valve lift 0.00216m:
Valve lift 0.0033m:
Valve lift 0.0045m:
Valve lift 0.0056m:
Valve lift 0.00683m:
Valve lift 0.008m:
The pressure value decreases with increase in the valve lift or valve opening. As the valve lift value increases, the fluid rush towards the low pressure region. So the pressure at the inlet manifold decreases with increase in valve opening.
Velocity flow trajectories:
Valve lift 0.001m:
Valve lift 0.00216m:
Valve lift 0.0033m:
Valve lift 0.0045m:
Valve lift 0.0056m:
Valve lift 0.00683m:
Valve lift 0.008m:
Valve lift vs mass flow rate:
Based on the valve lift value the mass flow rate value differes. Mass flow is the rate of fluid passes per unit time. The mass flow rate for all the 7 valve lift values are obtained.
The mass flow rate value increases with increase in valve lift value with the negative sign. The negative sign indicates that the fluid leaves the apparatus. The value of valve lift 0.0169 kg/s at 0.001m valve lift increases to the value of 0.0705 kg/s at 0.008m valve lift. The plot that describes the change in mass flow rate with the valve lift value is shown below,
(Note: The negative sign indicates that the fluid leaves the flowbench)
Flow trajectories video:
The flow trajectories animation for the valve lift values 0.001m and 0.008m is shown below,
At 0.001m valve lift - https://youtu.be/fl3PHNeIHBQ
At 0.008m valve lift - https://youtu.be/r6KORcfMN4Q
CAD model:
https://drive.google.com/file/
Conclusion:
Thus the flowbench simulation exhibits various results,
- The maximum velocity region increases with increase in valve lift or valve opening.
- The maximum velocity region increases based on the amount of fluid flow inside the cylinder. The flow depends on the valve lift.
- Thus, the maximum velocity region increases with increase in valve lift.
- The maximum pressure value decreases with increase in valve lift or valve opening.
- The maximum pressure value 100980 Pa at valve lift 0.001m decreases to 95741 Pa at valve lift 0.008m.
- When the valve lift or valve opening is maximum, the more amount of fluid enters into the cylinder. There will be a free flow of fluid without any resistance.
- Thus the pressure value decreases with increase in valve lift.
- The flow trajectories shows the velocity at different places in the 3D flowbench model.
- The mass flow rate value increases with increase in valve lift value.
- When the valve lift value is maximum, the mass of fluid enters into the cylinder is maximum.
Thus the flowbench is modelled and the simulation is done.