This paper introduces a semi-analytical approach which enables one to deal with distorted inflow in axial fans or compressors. It is inspired by the classical parallel compressor (PC) theory but relies on local flow-loading coefficient formalism. applied non-uniform flow conditions study aerodynamic behavior of low-speed fan response upstream distortion. Experimental measurements and 3D RANS si...

In this paper we develop globally robustly stabilizing controllers for rotating stall and surge in multimode axial flow compressor models with uncertain pressure-flow compressor performance characteristic maps. Specifically, using Lyapunov stability theory, a novel switching nonlinear globally robustly stabilizing control law based on equilibria-dependent Lyapunov functions with converging doma...

This paper introduces a way of reducing the torque variation in scroll compressors. In a scroll compressor where radial compliance device such as the slider bush is used for the flank sealing, the orbiting scroll member is given the freedom of movement in the radial direction. When such an orbiting scroll member orbits around the nonorbiting scroll member whose center is offset from that of the...

The present paper is a numerical and experimental comparative study of hermetic and semi-hermetic reciprocating compressors working with carbon dioxide as fluid refrigerant against the conventional R134a hermetic compressors. When cooling conditions for one-stage compressor type (i.e., evaporation temperatures between 7.2oC and –10oC) have been considered, the numerical and experimental results...

In this paper, a novel implementation of 8x8 Multiplier using 4-2 Compressors is presented; which produces quick results, especially for use in Digital Signal Processors and in Microprocessors. This multiplier uses a new partial-product reduction format which consecutively reduces the maximum output delay. The new design of multiplier requires less number of MOSFET’s compared to Wallace Tree Mu...

In this paper we present a bit-oriented architecture for the digital Finite Impulse Response (FIR) filter with adaptive coefficients. Instead of using multipliers, the FIR operation is regarded as the summation of a larger number of operands. Our architecture utilizes two new word-level operand compressors, namely six-to-triple and six-to-double compressors. Both of these two compressors, multi...

In Japan, the refrigerant used in room air-conditioners has been changed from HCFC-22 (R-22) to R-410A, a blend of HFC-32 and HFC-125 (50/50 vt%), in order to protect the ozone layer. Generally, the miscibility between the refrigerant and refrigeration oil must be assured, because the oil needs to return to the compressor from the refrigeration cycle and lubricate the sliding parts. Alternative...

arguably, the natural gas transmission pipeline infrastructure in iran represents one of the largest andmost complex mechanical systems in the world. the optimization of large gas trunk lines known asigat results in reduced fuel consumption or higher capability and improves pipeline operation. in thecurrent study, a single-objective optimization was conducted for khormoj compressor station on t...

XML simplifies data exchange amongst disparate computers, but is notoriously verbose and has spawned development of a variety of XML compressors and binary formats. Some formats allow streaming access to the data without complete decompression. We present an XML test file corpus, akin to corpora such as the Canterbury corpus and a combined efficiency metric integrating compression ratio and spe...