• International Journal of Fluid Machinery and Systems
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• 제9권2호
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• pp.143-149
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• 2016

In this study, a method for the multi-objective optimization of an impeller for a centrifugal compressor using fluid-structure interaction (FSI) and response surface method (RSM) was proposed. Numerical simulation was conducted using ANSYS CFX and Mechanical with various configurations of impeller geometry. Each design parameter was divided into 3 levels. A total of 15 design points were planned using Box-Behnken design, which is one of the design of experiment (DOE) techniques. Response surfaces based on the results of the DOE were used to find the optimal shape of the impeller. Two objective functions, isentropic efficiency and equivalent stress were selected. Each objective function is an important factor of aerodynamic performance and structural safety. The entire process of optimization was conducted using the ANSYS Design Xplorer (DX). The trade-off between the two objectives was analyzed in the light of Pareto-optimal solutions. Through the optimization, the structural safety and aerodynamic performance of the centrifugal compressor were increased.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.47-50
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• 2003

Hot-forging Process and die design was made for a large-scale compressor wheel of Ti-6Al-4V alloy with 2-D FE analysis. The design integrated the geometry-controlled approach and dynamic materials modelling(DMM). In order to obtain the processing contour map of Ti-6Al-4V alloy based on DMM, compression tests were carried out in the temperature range of 915$^{\circ}C$ to 1015$^{\circ}C$ and the strain range of 10$\^$-3/s$\^$-1/ to 10s$\^$-1/. In the die design of the compressor wheel using the rigid-plastic FE analysis, forging dimensional accuracy, the capacity of the forging machine and defect-free forging were considered as main design factors. The microstructure of hot forged wheel using the designed die showed a typical alpha-beta structure without forging-defects.

• 대한기계학회논문집B
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• 제24권1호
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• pp.39-49
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• 2000

This paper presents the modeling approach that can predict transient behavior of rotary compressor. Mass and energy conservation laws are applied to the control volume, real gas state equation is used to obtain thermodynamic properties of refrigerant. The valve equation is solved to analyze discharge process also. Dynamic analysis of vane and roller is carried out to gain friction work. From the above modeling, the performance of rotary compressor with radial clearance and friction loss is investigated numerically. The performance of each refrigerant is estimated, respectively by applying R12, R134a, and R290/ R600a mixture.

• 한국유체기계학회 논문집
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• 제7권3호
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• pp.23-31
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• 2004

An experimental study on the performance and instability development characteristics of a centrifugal compressor equipped with an adjustable inlet guide vane has been performed with varying guide vane angles. The test was conducted at the design speed of 20,800 rpm for 6 guide vane angles : $-30^{\circ},\;-20^{\circ},\;10^{\circ},\;0^{\circ},\;10^{\circ},\;20^{\circ},\;30^{\circ}$. Unsteady pressures were measured using high-frequency pressure transducers at the inducer to investigate the instability phenomena such as rotating stall and surge inside the compressor. From the unsteady measurements, it is found that the transient process from rotating stall to surge was mainly affected by inlet guide vane angles. The results of the present study can be applied to the instability control of the centrifugal compressors using a adjustable inlet guide vane.

• 동력기계공학회지
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• 제2권3호
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• pp.15-20
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• 1998

An integrated computing system has been developed for a Navier-Stokes design procedure of an axial-flow compressor blades. The process is done on the four separate steps, i.e., determination of the basic profiles, generation of computational grids, cascade flow simulation and analysis of the computed results in design sense. Applications are made to the blade design of the LP compressor. Computational results are analyzed with respect to the flow-field characteristics and are compared with the expected design requirements. The present system are coupled with the design procedure of the turbomachinery blades using the Navier-Stokes technique.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2000년도 유체기계 연구개발 발표회 논문집
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• pp.176-183
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• 2000

The performance of gas turbines decreases as their operating hours increase. Compressor fouling is the main reason for this time-dependent performance degradation. Airborne particles adhere to the blade surface and results in the change in the blade shape. It is difficult to exactly analyze the mechanism of the compressor fouling because the growing process of the fouling is very slow and the dimension of the fouled depth is very small compared with blade dimensions. In this study, an analytic method to predict the motion of particles and their deposition inside axial flow compressors is proposed. The analytic model takes into account the blade shape and the flow within the blade passage. Comparison of simulation result with field data shows the feasibility of the model. Influence of the particle distribution on the compressor fouling is also examined.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.385.2-385
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• 2002

Hermetic rotary compressor is one of the most important components for air conditioning system since it has a great effect on both the performance and the noise and vibration of the system. Noise and vibration of rotary compressor is occurred due to gas pulsation during compression process and unbalanced dynamic force. In order to reduce noise and vibration, it is necessary to identify sources of noise and vibration and effectively control them. (omitted)

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1429-1436
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• 2000

Suction muffler is one of the important component of a compressor for low noise level and high efficiency. The suction muffler which has the complicated flow path gives the higher transmission loss of sound, but lower efficiency of compressor results from the superheating effect and flow loss in suction flow path. It is shown that the computational analysis of fluid dynamics are very popular methods for designing of high performance and low noise suction muffler. To reduce the thermodynamic and flow loss in suction process, the flow path of suction muffler was estimated by FVM(Finite Volume Method) and verified by experiments. And to enlarge the transmission loss of sound, the acoustic properties inside the suction muffler was analyzed by FEM(Finite Element Method) and experiments. The smart muffler which gives a good efficiency and low noise character was developed by using those methods, and the effect was evaluated in compressor by experiment.

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.939-944
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• 2004

The numerical methods including the performance analysis and the noise prediction of the centrifugal compressor impeller are coupled with the optimization design skill, which consists of response surface method, statistical approach, and genetic algorithm. The flow-field Inside of a centrifugal compressor is obtained numerically by solving Wavier-Stokes equations. and then the propagating noise is estimated from the distributed surface pressure by using Ffowcs Williams-Hawkings formulation. The quadratic response surface model with D-optimal 3-level factorial experimental design points is constructed to optimize the impeller geometry for the advanced centrifugal compressor. The statistical analysis shows that the quadratic model exhibits a reasonable fitting quality resulting in the impeller blade design with high performance and low far-field noise level. The influences of selected design variables, objective functions, and constraints on the impeller performance and the impeller noise are also examined as a result of the optimization process.

• Tribology and Lubricants
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• 제12권2호
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• pp.20-31
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• 1996

Pressures in compression pockets consists of two identical spiral scrolls are influenced by gas flow resistance in discharge process and leakages in radial and tangential directions between two scroll wraps. In this paper, considering geometrical characteristics of these members, flow resistance and refrigerant gas leakage losses, pressure variations in compression pockets are calculated. For a scroll compressor model with fixed crank mechanism, acting load on crankshaft is analyzed. And, for a vertical type crankshaft-journal bearing system used in scroll compressor, nonlinear transient response is calculated including nonlinear fluid film reaction forces of journal bearings.