MBD Simulation on a Piston Assembly

PROJECT REPORT

MBD SIMULATION ON A PISTON ASSEMBLY

OBJECTIVE : The aim of this project is to perform MBD simulation of the piston assembly of an engine in Solidworks for 3 different cases and do the required post processing. The three cases are as follows:

Case 1: Piston at neutral position with regards to crankshaft.

Case 2: Piston at 10 mm positive offset with regards to crankshaft

Case 3: Piston at 10 mm negative offset with regards to crankshaft.

INPUT PARAMETERS :

Case No.	Offset	Crank Speed	Crank Rotation	Frame per second
1.	0 mm	2000 RPM	ClockWise	12000
2.	10 mm - Positive	2000 RPM	ClockWise	12000
3.	10 mm - Negative	2000 RPM	ClockWise	12000

PROCEDURE :

FIRST, Design different components of the piston assembly one by onein the part design workbench.

SECOND, Assemble different components with proper mates and Dimensional constraint. Ensure, linear motion for the piston and the rotational motion of the crankshaft is present.

THIRD, Open solidworks motion add-on & a provide a rotary motor to the crankshaft with 2000 RPM. Also, provide contact constraints between differnet components of the assembly. Select materials equal to steel(dry).

FOURTH, Turn On precise contact in the settings and give the frames per second equal to 12000.

FIFTH, Run the simulation for a short intervals so that minimum 3-4 full crankshaft rotations were achived. Repeat all these steps for the 3 cases also.

SIXTH, Evaluate Results.

CAD MODELS :

CASE 1 : Piston at neutral position with regards to crankshaft. (Offset = 0 mm)

CASE 2 : Piston at 10 mm positive offset with regards to crankshaft.

CASE 3 : Piston at 10 mm negative offset with regards to crankshaft.

RESULTS :

1. PLOT : Linear displacement of the Piston Head VS Time

CASE 1 : Piston at neutral position with regards to crankshaft. (Offset = 0 mm)

CASE 2 : Piston at 10 mm positive offset with regards to crankshaft.

CASE 3 : Piston at 10 mm negative offset with regards to crankshaft.

2. COMBINED EXCEL PLOT FOR ABOVE 3 CASES

CONCLUSION :

1. From the above three plot it is clearly observed that, The positive offset piston reaches TDC and BDC faster than the negative offset piston & zero offset piston.

2. Increasing order of Angular Speed : Positve > Neutral > Negative