Compact aero-engines that use centrifugal compressors are in high demand due to their small size and cost-effectiveness. However, limited improvements the aerodynamic performance of impellers have led a greater focus on improving diffusers. This paper introduces novel vane conformal diffuser designed match an impeller with pressure ratio. The utilizes unique design method creates transitions fr...

Dry screw compressor are limited to maximum pressure ratios of approximately 3:1 due to the high gas temperatures resulting from the compression process, which cause them to deform To attain higher pressure ratios the compressors must be cooled. The main features of heat transfer in screw compressors are reviewed qualitatively and resulting from this, an analytical and experimental study was ca...

Chirped X-ray pulse compression is a promising approach for generating ultra-short free electron laser (XFEL) pulses. The design of compressors requires the careful control group delay dispersion (GDD), which plays critical role in achieving optimal compression. However, penetration crystals and multilayers can induce an extra GDD, may result over-compression or under-compression. In this study...

Compression of pure refrigerants in the two-phase flow region has a number of advantages for the performance of vapor compression systems. Compressors may be lubricated by liquid refrigerant so that the process side of the cycle is not contaminated by lubricant. The compression process can be realized in the two-phase region preventing superheating with its associated irreversibility losses. Th...

This paper presents a feasibility study of evolutionary scheduling for gas pipeline operations. The problem is complex because of several constraints that must be taken into consideration during the optimization process. The objective of gas pipeline operations is to transfer sufficient gas from gas stations to consumers so as to satisfy customer demand with minimum costs. The scheduling involv...

When we design a valve system there are many design factors and their values to decide. Generally, design factors which affect the whole performance of compressors are strongly related to each other so we can't decide the value of each design factors respectively. In order to decide the optimum value (among levels) of those factors simultaneously and reduce the number of experiments we applied ...

Over the years, rotary compressors have gained significant popularity and widespread usage because of their compact nature and good vibration characteristics. Although possessing many advantages over the reciprocating compressors, one of the performance limitations of the rotary machines is their inferior mechanical efficiency due to the existence of large frictional losses, which occurs as a r...

This paper is intended as a review of the recent research and development of refrigeration and gas compressors in Japan. The review has been carried out by the papers as source material that are reported in the transactions, proceedings, and magazines in mechanical engineering field. Most compressor companies in Japan have long efforted to develop and apply advanced technology for innovative re...

This paper presents a complete dynamic analysis of roller and vane of a rotary compressor widely used for air-conditioners. An approach and a set of equations are developed estimating the type of motion at vane tip and roller interface and calculating the frictional force in accordance with the motion type. The forces on roller caused by relative motion between roller and cylinder wall are anal...

The physical performance characteristics of composite materials used for vanes in rotary, sliding-vane compressors, in general, are several orders of magnitude more difficult to quantify for design purposes than most homogeneous materials. This arises from the numerous variables that influence the response of these materials under the severe environmental conditions existing in such compressors...