In both nature and engineering, loosely packed granular materials are often compacted inside confined geometries. Here, we explore such behavior in a quasi-two dimensional geometry, where parallel rigid walls provide the confinement. We use the discrete element method to investigate the stress distribution developed within the granular packing as a result of compaction due to the displacement o...

The first phase of a project at Sunpower, Inc. sponsored by the EPA is described. The program involves the design, computer simulation and fabrication of a high efficiency linear compressor for application in domestic refrigeration. The use of a high efficiency electric motor and non-contact operation can dramatically reduce the electrical and friction losses associated with crank compressors. ...

This article presents the results of research into causes wear piston pin mounted in bosses by means a hinge joint and connecting rod small end thermocompression bond. Changes geometry pin-top surface structure, which are caused mutual influence mating surfaces variable lubrication conditions, presented. The progress scuffing as result insufficient elements or oil film breaking is demonstrated....

In this paper a full transient 3-D CFD model of a complete single piston compressor system along with dynamic inlet and outlet port flip valves is presented. The model includes the motion of the cam driven piston, and also predicts the motion of the dynamic flip valves. All activities related to model creation, simulation and postprocessing were performed within the simulation software Simerics...

The bowl-to-bowl inversion of the non-planar bowl-shaped compounds derived from sumanene as a fullerene C3v fragment was found to be slow and tuned by a solvent, and the benzylic mono- and di-anions inverted even more slowly.

The steelpan is a pitched percussion instrument that takes the form of concave bowl with several localized dimpled regions varying curvature. Each these zones, called notes, can vibrate independently when struck, and produce sustained tone well-defined pitch. While association zones individual notes has long been known exploited, relationship between shell geometry strength mode confinement rem...