The air conditioning and refrigeration systems noise consideration is continuously growing, implying more and more compressor noise measurements [1], even in-situ [2][3]. This article will introduce a new validated finite-element method to obtain the compressor noise from vibration measurements from standard test rig or directly in the field. We will describe the methodology; the devices & tool...

Generation of coherent short-wavelength radiation across a plasma column is dramatically improved under traveling-wave excitation (TWE). The latter is optimized when its propagation is close to the speed of light, which implies small-angle target-irradiation. Yet, short-wavelength lasing needs large irradiation angles in order to increase the optical penetration of the pump into the plasma core...

A better understanding of turbulent unsteady flows is a necessary step towards a breakthrough in the design of modern compressors. Owing to high Reynolds numbers and very complex geometry, the flow that develops in such industrial machines is extremely hard to predict. At this time, the most popular method to simulate these flows is still based on a Reynolds-averaged Navier-Stokes approach. How...

Mathematical models have been popularly applied to study the compression processes of superheated refrigerant vapor in compressors. As to the case when refrigerant enters a compressor cylinder in the state of liquid and vapor mixture, however, the availability of fundamental studies is very limited. -A mathematical model is presented to simulate the compression processes of two-phase saturated ...

Refering to figure 1 [Fig.1], an oscillating « flipper » piston (1) and its associated chamber (2) are maintained without reciprocal contact. No oil is required because there no contact so friction. An shaft (22) maintains the »piston (1). Around (22), a twisting seal (8) allows for absolute sealing. This characteristic important Stirling engines oil-free compressors. Referring 4 [Fig.4], two p...

The twin-screw compressor is constantly attaJ.ninq hiqher performance due to new rotor profiles, new rotor manufacturing technology and new designs. Besides this, new refrigerants as well as new lubricants can be expected on the market. Therefore there is always a need to update performance data. To m1nimize the number of test points and still receive representative data, there 1s a need of an ...

The AeroEclipse® BAN (Trudell Medical International (TMI), London, Canada) was initially developed for use in the hospital environment, optimized for medication delivery using air or oxygen supplied at 50 psig pressure (2, 3). This article describes initial laboratory data with a version (AeroEclipse-XL®) optimized for operation by either table-top (OmbraTM table-top compressor, TMI, 230V AC ve...

Design models of multi- stage, axial flow compressor are developed for gas turbine engines. Axial flow compressor is one of the most important parts of gas turbine units. Therefore, its design and performance prediction are very important. One-dimensional modeling is a simple, fast and accurate method for performance prediction of any type of compressors with different geometries. In this appro...

Due to the transcritical nature, some of the test methods used in the conventional subcritical refrigeration cycle, such as the liquid refrigerant flow metering method and the water-cooled condenser metering method, are no longer appropriate for evaluating the transcritical carbon dioxide (CO2) compressor performances. This paper introduces a performance test facility taken into account both th...