The piston shock problem is a classical result of shock wave theory. In this work, the analogous dispersive shock wave (DSW) problem for a fluid described by the nonlinear Schrödinger equation is analyzed. Asymptotic solutions are calculated for a piston (step potential) moving with uniform speed into a dispersive fluid at rest. In contrast to the classical case, there is a bifurcation of shock...

Decreasing production and rising prices of cars, especially those with electric drive, lead to longer use cars internal combustion engines. It can be assumed that in the future, more powered by such engines high mileage therefore wear will used. Engine leads reduced efficiency increased emissions. This paper analyzes impact piston–rings–cylinder system components on energy losses associated gas...

The materials used for the piston cylinders of automobile engines, or ring and tappets various mechanical components, are continuously experiencing lubricated sliding motions. These surfaces prone to damage due tribological aspects friction wear. Hence, enhancing their surface properties would contribute increasing life saving energy resources. For many decades texturing coating technology have...

A dynamic model of a free liquid piston that exploits piston geometry to produce a high inertance was developed for use in a free piston engine compressor. It is shown that for the size scale targeted, advantageous piston dynamics can be achieved with a reduced piston mass compared to a rigid piston design. It is also shown that the viscous losses associated with the liquid piston are negligibl...

in this note we introduce the notion of weak mccoy rings as a generalization of mccoy rings, and investigate their properties. also we show that, if is a semi-commutative ring, then is weak mccoy if and only if is weak mccoy.

Pressure and performance requirements of axial piston pumps and the proportion of churning losses in axial piston pumps increase significantly with increasing speed. To investigate the primary distribution of churning losses in axial piston pumps at various ranges of speed, a test rig was set up in which other friction losses can be eliminated, thus making it possible to investigate the net chu...

We calculate the scalar Casimir energy and Casimir force for a R×N Kaluza-Klein piston setup in which the extra dimensional space N contains a non-commutative 2sphere, SFZ . The cases to be studied are T d × SFZ and SFZ respectively as extra dimensional spaces, with T d the d dimensional commutative torus. The validity of the results and the regularization that the piston setup offers are exami...

This paper shows the mixed lubrication analysis between the vane tip and rolling piston in a rotary refrigerant compressor, coupling the motion equations of vane and rolling piston, the elastohydrodynamic lubrication (EHL) analysis of line contact and the equations of viscosity characteristics of lubricating oil as a function of oil pressure, oil temperature and concentration of refrigerant. Th...

All conventional piston-driven combustion engines emit metal oxide particles. The main sources are the abrasion between piston-ring and cylinder, abrasion in the bearings, catalyst coating, lube-oil additives, and fuel additives for promoting the exhaust-gas after-treatment. Metal oxides, especially from transition metals, are very toxic when they are very fine. These particles have a high BET ...

The internal combustion engine will be required as a bridge-technology in the upcoming decades to achieve significant reduction local emissions mobility, and logistics sector. Alternative fuel technologies present new mechanical engineering challenges, including increasing efficiency reducing losses. Textured surfaces with appropriate manufacturing parameters can enhance lubrication, reduce fri...