• 한국유체기계학회 논문집
• /
• 제10권2호
• /
• pp.22-31
• /
• 2007

This paper describes the shape optimization of rotor blade in a transonic axial compressor rotor. Three surrogate models, Kriging, radial basis neural network and response surface methods, are introduced to find optimum blade shape and to compare the characteristics of object function at each optimal design condition. Blade sweep, lean and skew are considered as design variables and adiabatic efficiency is selected as an objective function. Throughout the shape optimization of the compressor rotor, the predicted adiabatic efficiency has almost same value for three surrogate models. Among the three design variables, a blade sweep is the most sensitive on the object function. It is noted that the blade swept to backward and skewed to the blade pressure side is more effective to increase the adiabatic efficiency in the axial compressor Flow characteristics of an optimum blade are also compared with the results of reference blade.

• International Journal of Fluid Machinery and Systems
• /
• 제2권1호
• /
• pp.1-12
• /
• 2009

Surrogate modeling is applied to a compressor blade shape optimization to modify its stacking line and thickness to enhance adiabatic efficiency and total pressure ratio. Six design variables are defined by parametric curves and three objectives; efficiency, total pressure and a combined objective of efficiency and total pressure are considered to enhance the performance of compressor blade. Latin hypercube sampling of design of experiments is used to generate 55 designs within design space constituted by the lower and upper limits of variables. Optimum designs are found by formulating a PRESS (predicted error sum of squares) based averaging (PBA) surrogate model with the help of a gradient based optimization algorithm. The optimum designs using the current variables show that, to optimize the performance of turbomachinery blade, the adiabatic efficiency objective is improved substantially while total pressure ratio objective is increased a very small amount. The multi-objective optimization shows that the efficiency can be increased with the less compensation of total pressure reduction or both objectives can be increased simultaneously.

• 대한기계학회논문집B
• /
• 제29권5호
• /
• pp.625-632
• /
• 2005

This paper describes the shape optimization of a stator blade in a single-stage transonic axial compressor. The blade optimization has been performed using response surface method and three-dimensional Navier-Stokes analysis. Two shape variables of the stator blade, which are used to define a stacking line, are introduced to increase an adiabatic efficiency. Data points for response evaluations have been selected by D-optimal design, and linear programming method has been used for an optimization on a response surface. Throughout the shape optimization of a stator blade, the adiabatic efficiency is increased to 5.8 percent compared to that of the reference shape of the stator. The increase of the efficiency is mainly caused by the pressure enhancement in the stator blade. Flow separation on the blade suction surface of the stator is also improved by optimizing the stator blade. It is noted that the optimization of the stator blade is also useful method to increase the adiabatic efficiency in the axial compressor as well as the optimization of a rotor blade, which is widely used now.

• 대한기계학회논문집B
• /
• 제30권7호
• /
• pp.622-629
• /
• 2006

The shape optimization of blade sweep in a transonic axial compressor rotor of NASA Rotor 37 has been performed using response surface method and the three-dimensional Wavier-Stokes analysis. Two shape variables of the rotor blade, which are used to define the rotor sweep, are introduced to increase the adiabatic efficiency of the compressor. Throughout the optimization, optimal shape having a backward sweep is obtained. Adiabatic efficiency, which is the objective function of the present optimization, is successfully increased. Separation line due to the interference between a shock and surface boundary layer on the blade suction surface is moved downstream for the optimized blade compared to the reference one. The increase in adiabatic efficiency for the optimized blade is caused by suppression of the separation due to a shock on the blade suction surface.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
• /
• pp.437-442
• /
• 2004

The optimization of a blade sweep for a transonic axial compressor rotor (NASA rotor 37) has been performed using a response surface method and a Reynolds-averaged Wavier-Stokes (RANS) flow simulation. Two shape variables of the rotor blade, which are used to define a blade sweep, are introduced to increase an adiabatic efficiency. Data points for response evaluations have been selected by D-optimal design, and linear programming method has been used for an optimization on a response surface. The result shows that the adiabatic efficiency is increased to about 1 percent compared to that of the reference shape of the rotor blade. Relatively high increasement of the adiabatic efficiency is obtained between 20 and 60 percent span. In the present study, backward swept blade is more effective to increase the adiabatic efficiency In the axial compressor rotor.

• 대한기계학회논문집B
• /
• 제37권2호
• /
• pp.149-154
• /
• 2013

본 연구는 7kW 모터로 $18.5m^3/min$의 유량을 양정(H) 0.5m로 공급할 수 있는 고농도 폐수처리용 3엽 수중 펌프의 블레이드를 개발하는 것을 목표로 한다. 이를 위해 블레이드의 축방향 비틀림 각, 블레이드의 길이 및 반경방향 비틀림 각을 설계변수로 선정하여 이들이 블레이드 효율에 미치는 영향을 상용 해석용 프로그램을 사용한 (ANSYS BladeGen, Turbo Grid, CFX) 전산해석을 통해 수행하였다. 해석 결과 블레이드의 축방향 비틀림각(${\beta}$)가 펌프의 효율에 가장 민감한 변수임을 알 수 있었으며, 축방향 비틀림각 $({\beta})=20^{\circ}$, 반경방향 비틀림 각 $({\alpha})=110^{\circ}$ 그리고 블레이드의 길이 (l)=240 mm 일 때 펌프의 최고 효율을 가지게 됨을 알 수 있었다.

• 한국유체기계학회 논문집
• /
• 제17권4호
• /
• pp.19-29
• /
• 2014

In addition to the development of micro hydro turbine, the challenge in micro hydro turbine design as sustainable hydro devices is focused on the optimization of turbine runner blade which have decisive effect on the turbine performance to reach higher efficiency. A multi-objective optimization method to optimize the performance of runner blade of propeller turbine for micro turbine has been studied. For the initial design of planar blade cascade, singularity distribution method and the combination of the Bezier curve parametric technology is used. A non-dominated sorting genetic algorithm II(NSGA II) is developed based on the multi-objective optimization design method. The comparision with model test show that the blade charachteristics is optimized by NSGA-II has a good efficiency and load distribution. From model test and scale up calculation, the maximum prototype efficiency of the runner blade reaches as high as 90.87%.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
• /
• pp.149-155
• /
• 2001

Recently, it is required to design higher stage pressure ratio compressor while maintaining equal adiabatic efficiency. To increase the stage pressure ratio, blade rotational speed or diffusion factor should be increased. In the case of increasing rotational speed, relative speed of flow at blade leading edge is well supersonic. In supersonic blade, total pressure loss is mainly due to shock wave and blade leading edge thickness should be very thin to minimize the shock wave loss. As a result, the blade is like to be week in terms of mechanical strength and the manufacturing cost is very high because NC machining is necessary. It is also one of big hurdle to overcome to make small compressor. In this paper, the effects of blade leading edge to the performance of supersonic blade In terms of total pressure loss. The efficiency of already known method to make thin blade leading edge from the casted blade with rather thick leading edge thickness is also assessed.

• 한국정밀공학회지
• /
• 제30권9호
• /
• pp.977-982
• /
• 2013

Blades of wind energy plants are exposed to external shocks or internal cracks during operation. Furthermore, the blade surfaces can be contaminated by substances such as dust, blood of birds, salt or insects which can decrease the electricity generation efficiency significantly. For this reason, many blade cleaning companies started to appear and a variety of methods for cleaning were suggested. Despite these diverse methods, there has been no study to investigate how effectively to clean the substances in quantitative manner. In this paper, the cleaning efficiency of two rotor blade cleaning methods, brush and water-jet, is examined through experiments by changing operating parameters. Then, the optimal operating conditions for both methods are derived.

• 한국유체기계학회 논문집
• /
• 제9권3호
• /
• pp.7-13
• /
• 2006

Shape optimization of a rotor blade in a single-stage transonic axial compressor has been performed using a response surface method and three-dimensional Navier-Stokes analysis. Two shape variables of the rotor blade, which are used to define a blade skew, are introduced to increase an adiabatic efficiency. Throughout the shape optimization of a rotor blade, the adiabatic efficiency is increased to about 2.2 percent compared to that of the reference shape of the stator. The increase in efficiency for the optimal shape of the rotor is due to the pressure enhancement, which is mainly caused by moving the separation position on the suction surface of rotor blade to the downstream direction.