Through the sound spectrum analysis, this paper indicates that the noise peak frequency comes from mechanical shock, investigating the frequencies of noise sources, the noise peak frequency is found --the impact pairs of the valve plate and the spring~ The cause to raise the noise is on the phenomenon detachment between the valve plate and the spring. For this reason the valve plate produces hi...

Centrifugal compressors are a key piece of equipment for modern production. Among the components of the centrifugal compressor, the impeller is a pivotal part as it is used to transform kinetic energy into pressure energy. Blade crack condition monitoring and classification has been broadly investigated in the industrial and academic area. In this research, a pressure pulsation (PP) sensor arra...

The effects of compressor speed variation on the heat transfer inside a speed controlled compressor were investigated in this study. Based on the lumped capacitance ntethod, the temperatures of the compressor components, the oil, and the refrigerant gas within the shell were modeled and simulated on a relative scale. A diffenmt heat transfer coefficient correlation was developed to evaluate the...

2 Abstract Pneumatic actuators have several advantages such as light weight, safety, low cost and high compliance. However, many pneumatic actuators have complicated systems that include a compressor, air tubes, and pneumatic valves with electrical wires. This research proposes a new control method for a multiplex pneumatic transmission constructed with special resonant valves and air tubes wit...

Chapter 2 describes the various concepts of Active Component Control that can help to meet future engine requirements by an active improvement of the component characteristics. The concept is based on an intelligent control logic, which senses actual operating conditions and reacts with adequate actuator action. This approach can directly improve engine characteristics as performance, operabili...

The optimum design of a flexible rotor supported on three-lobe bearings, overhung centrifugal compressor, is studied for the optimal unbalance response using the genetic algorithm (GA) and method of feasible directions (MFD). The MFD is used to verify the GA results. The feasibility, effectivness, and avaliability of the GA is certainly of value because it allows the exploration of many differe...

This paper is concerned with modeling and active vibration control of a 1.23-m long flexible shaft on active magnetic bearings that is designed to model a small industrial compressor and to serve as a platform for investigating emerging control schemes. Aerodynamic cross-coupled stiffness is one of the main contributors to rotordynamic instability in modern turbo-machines. The destabilizing eff...

The search for energy-efficient technologies for developing new refrigerator appliances has made the magnetocaloric effect a field of current scientific interest.1 The number of scientific publications on this topic is increasing exponentially in the recent years (Figure 1), which is proof of the high expectations that the scientific community is depositing on this field of research. Together w...

A Burrows-Wheeler Compressor breaks input into blocks, quickly makes each more compressible, and compresses the modified block with a simple arithmetic or Huffman compressor. We propose an error-resilient Inverse Burrows-Wheeler Compressor. It uses a small amount of overhead alongside output from an ordinary BWT and MTF. It is also size-competitive with BZIP, a popular Burrows-Wheeler compressor.

The presence of noises in the vehicle cabin is an annoyance phenomenon which significantly affected by heating, ventilation, and air conditioning (HVAC) system. There are very limited studies reported on specific type noise characterisation validation for both model system levels. present study developed a HVAC that reflects operation as real vehicle, investigation components were carried out i...