A plain journal bearing is spontaneously unstable above a critical speed and loses much of its load carrying capacity when subjected to a load rotating at about half the speed of the shaft. The almost axially symmetric flow in a compressor can break down at low flow into a rotating pattern of stall cells but only the special case of a single propagating stall cell gives rise to a mechanical cou...

Scheming multipliers that are of high-speed, low power, and standard in design are of substantial research interest. By reducing the generated partial products speed of the multiplier can be increased. Several attempts have been made to decrease the number of partial products generated in a multiplication process. One of the attempt is Wallace tree multiplier. This paper aims at designing and i...

In a distributed environment, large data files remain a major bottleneck. Compression is an important component of the solutions available for creating file sizes of manageable and transmittable dimensions. When high-speed media or channels are used, high-speed data compression is desired. Software implementations are often not fast enough. In this paper, we present the very high speed hardware...

In this paper, a buck half-bridge DC-DC converter is used as a single-stage power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (PMBLDCM) drive. The front end of this PFC converter is a diode bridge rectifier (DBR) fed from single-phase AC mains. The PMBLDCM is used to drive a compressor load of an air conditioner through...

Field testing of compressor packages driven by gas turbines or electric motors requires the accurate determination of efficiency, flow, head, and power in sometimes less than ideal working environments. This paper discusses field performance testing of centrifugal compressors and measurement uncertainties one can expect when following appropriate test guidelines. The primary focus is on compres...

Field Programmable Gate Array (FPGA) technology has become a viable target for the implementation of algorithms in different compression methods applications. In a distributed environment, large data files remain a major bottleneck. Compression is an important component of the solutions available for creating file sizes of manageable and transmittable dimensions. When high-speed media or channe...

This paper presents a stability investigation of the step recessed, hydro-static and -dynamic hybrid water-lubricated journal bearings for fuel cell vehicle compressor. The dynamic coefficients and stability threshold speed of the bearings are numerically calculated by solving the turbulent Reynolds equation by using FEM. Two configuration bearings are comparatively studied and the different dy...

This paper presents generic equipment models that capture the performance of families of similar heat pumps equipment and that can be used in building simulation programs. Mapping has been carried out for families of single and dual compressor speed ducted split systems and the correlations are being implemented as components for building simulation. The units mapped ranged in nominal capacity ...

Variable-speed centrifugal compressors are used in a wide variety of industries and applications, including natural gas pipelines and processing plants, oil refineries and chemical plants, air-separation units, refrigeration and air conditioning equipment refrigerant cycles, gas turbines and auxiliary power generators, and many more. Some natural gas plants, for example, employ a propane-precoo...