How to accurately describe piston vectors

[cdrazic93]

I am very curious as to know how this works, as I am very passionate about cars, and how they work. I already tried using the search function, and nothing to my knowledge concerning piston vectors came up.

Today in my math class, my professor was talking about vectors in the general sense, which made me start thinking about how I can apply the mathematical term of vectors to a car piston, since I am new to the mathematical side of the engineering world, would anyone care to explain how this is written or achieved? What forces would be acting on the piston head other than: combustion, oil friction, crank resistance and gravity?

 

[Lou Scannon]

Crankcase pressure, and any linear or rotational accelerations of the engine in which the piston is running, i.e. if the car is accelerating, turning, cresting a hill, for instance.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[ivymike]

Side loads from the rod and block
plus a ton of forces and moments that come about due to the secondary motion

 

[dgallup]

Do you know how to do a free body diagram? Basically show the piston in space and draw the vectors for the gas forces, cylinder wall & rod. For a static condition sum of the forces = zero in all 3 directions. Since a static piston is rarely an interesting condition, F=ma for all 3 directions.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[tbuelna]

Any free body has 6 potential kinematic DoF's. 3 linear and 3 rotational. An engine piston is fully constrained in both the linear and rotational DoF's. So all of the dynamic and combustion pressure forces acting on the piston must be resolved about the piston's center of mass and the piston's kinematic constraints, rather than the piston's "head".

 

[desertfox]

Try this site

http://www.freestudy.co.uk/dynamics/velaccdiag.pdf

 

[loki3000]

depending on what are you trying to achieve, there is no need for side forces, as the normal ones are much greater (normal to surface of piston)