Project

MBD STIMULATION ON A PISTON ASSEMBLY

PPugazhendhi Gopal9 Jun 2020

AIM

To perform Multi Body Dynamics Simulation on a piston assembly.

OBJECTIVES

To perform motion analysis at different wrist pin position and to plot the linear displacement of the piston head for the following cases

S.NO	Wrist Pin Offset	RPM
1	0 mm	2000
2	10 mm positive	2000
3	10 mm negative	2000

THEORY

Piston is one of the component of an internal combustion engine. The main function of the piston is to transfer the pressure generated by burning air-fuel mixture into a force acting on crankshaft. The following are the different parts of the piston

Piston Head
Connecting rod
Crankshaft
End Plate
Wrist pin

PISTON HEAD

Piston head is the top part of the piston which directly comes in contact with the gas pressure within the combustion chamber. The piston head consists of piston rings. The following are the major functions of a piston ring

The piston ring seals the cylinder so that the combustion gas generated at the time of ignition does not leak into the opening between the piston and the cylinder. If this happens, there will be increase in fuel consumption and the engine will not produce sufficient power
Since the gas ignition is repeated several times, the piston goes up and down inside the engine at a rate of several thousand times per minute. A small amount of oil is poured over the piston so that they move smoothly and to reduce the friction between them. Piston rings is used to adjust the flow of oil.
The temperature inside the piston will be high when the ignition takes place and accumulation of heat over long time can damage the piston. Piston rings are used to transfer the heat from the piston crown to the cylinder.

CONNECTING ROD

The connecting rod connects the piston head with the crank shaft. The major function of the connecting rod is to convert the reciprocating motion of the piston to rotary motion of the crank shaft.

The following are the 3D CAD models for connecting rod and end cap.

WRIST PIN

Wrist pin also know as gudgeon pin is used to connect the connecting rod with the piston head.

CRANK

A series of crank are connected together to form a crank shaft. One end of the connecting rod is connected to the crank. The function of crank shaft is to convert the reciprocating motion of the piston into rotary motion.

ASSEMBLY MODEL OF PISTON

MOTION ANALYSIS SETUP

The various parts are modelled with the given dimension.
Assembly of the piston is done by providing the required mates conditions.
Motion analysis can be enabled by selecting the SOLIDWORKS Add-Ins.
Under the motor tab, rotary motor is selected and the axis of rotation is also specified.
Contact between the bodies is enabled by selecting the contact tab.
Results and Plot tab is selected and the required conditions are specified.

0mm OFFSET POSITION

3D MODEL

Linear displacement of the piston head with 0 mm offset position

10mm Negative offset

3D MODEL

Linear Displacement of piston head with 10 mm negative offset

10 mm Positive offset

3D MODEL

Linear Displacement of piston head with 10 mm positive offset

YOUTUBE LINK

https://youtu.be/kzlb8dvo-Cs

PART DRAWING