• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.771-776
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• 2001

By matching a well established fast throughflow code, with standard loss correlations, and an efficient optimization algorithm, a new design system has been developed, which optimizes inlet and exit flow-field parameters for each blade row of a multistage axial flow turbine. The compressible steady state inviscid throughflow code based on streamline curvature method is suitable for fast and accurate flow calculation and performance prediction of a multistage axial flow turbine. A general purpose hybrid constrained optimization package, iSIGHT has been used, which includes the following modules: genetic algorithm, simulated annealing, modified method of feasible directions. The design system has been demonstrated using an example of a 5-stage low pressure steam turbine for 800MW thermal power plant previously designed by HANJUNG. The comparison of computed performance of initial and optimized design shows significant improvement in the turbine efficiency.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.271-272
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• 2015

Gas turbine combustors is critical part due to high temperature operating conditions and the optimization of cooling design is required to avoid combustor failure. In gas turbine combustor, effusion cooling, impingement cooling and thermal barrier coating (TBC) are commonly used to improve cooling characteristics. In conceptual design, these cooling schemes are designed by 1D heat transfer calculation. Therefore, these design should be validated ted by nemurical or experiment methods. In this study, Conjugate Heat Transfer (CHT) analysis is performed for validation of gas turbine combustor cooling design.

• 한국유체기계학회 논문집
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• 제11권1호
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• pp.33-39
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• 2008

Hybrid power generation systems combining a solid oxide fuel cell and a gas turbine is promising due to their high efficiency. In the pressurized hybrid system, the operating condition of the gas turbine may play a critical role in designing the hybrid system. In particular, prevention of surge of the compressor can be a critical issue. The existence of fuel cell between the compressor and the turbine may cause an additional pressure loss and thus compressor operating points tend to approach the surge if the original turbine inlet temperature is pursued. In this study, bypassing some of the turbine inlet gas directly to the turbine exit side is simulated. Its effects on suppressing the surge problem and change in performance characteristics are discussed.

• 대한기계학회논문집
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• 제18권8호
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• pp.2167-2176
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• 1994

This paper presents some useful design criteria for the turbine cogeneration system through both the design and off-design analysis. Comparative analysis of the part load performance is carried out for several gas turbines which have different design parameters represented by the turbine inlet temperature and pressure ratio. It is shown that the variation in part load efficiency considerably depends on the design parameter. The off-design operation of the heat recovery steam generator is simulated by introducing adequate assumptions for the heat transfer process. It is turned out that the design parameters of heat recovery steam generator should be determined by considering the favorable operation at the off-design conditions.

• International Journal of Fluid Machinery and Systems
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• 제7권2호
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• pp.68-79
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• 2014

The type of turbine developed is based on the very low head of water potential source for the electric power production. The area of research is focused for the axial water turbine that can be applied at the simple site open channel with has a very low cost and environmental impact compared to the conventional hydro installation. High efficiency of axial turbine which applied to the very low potential head will made this type of turbine can be used at wider potential site. Existing irrigation weir and river area will be the perfect site for this turbine. This paper will compare the effects of the variation of swirl velocity criterion during the design of the blade of guide vane and rotor of the turbine. Effects of the swirl velocity criterion is wider known as a vortex conditions (free vortex, force vortex and swirl velocity constant), and the free vortex is the very popular condition that applied by most of turbine designer, therefore will be interesting to do a comparison against other criterion. ANSYS Fluent will be used for simulation and to determine the predictive performance obtained by each of design criteria.

• 한국유체기계학회 논문집
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• 제15권6호
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• pp.39-45
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• 2012

This paper describes the outcome of the design of a 200 kW class micro gas turbine and the sensitivity of its performance (efficiency and power) to the variations in major design parameters. The reference design parameters were set up based on the best available component technologies. The resulting net electricity generation efficiency of the micro gas turbine package was found to be competitive to those of other systems in the market. The sensitivities of power and efficiency to the variations in compressor and turbine efficiencies, pressure ratio, turbine inlet temperature, recuperator effectiveness, secondary air ratio, pressure loss ratios of both the cold and hot sides of the recuperator were estimated. Based on the sensitivity data, a simplified method to predict the variation in system performance responding to the combinations of small changes in all design parameters were set up and validated.

• 대한조선학회논문집
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• 제51권1호
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• pp.78-87
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• 2014

Recently the offshore wind turbine development is requested to be installed off south-west coast and Jeju island in Korea. Reliable and robust support structures are required to meet the demand on the offshore wind turbine in harsh and rapidly varying environmental conditions. Monopile is the most preferred substructure in shallow water with long term experiences from the offshore gas and oil industries. This paper presents an optimum design of a monopile connection with grouted transition piece (TP) for the reliable and cost-effective design purposes. First, design loads are simulated for a 5 MW offshore wind turbine in site conditions off the southwest coast of Korea. Second, sensitivity analysis is performed to investigate the design sensitivity of geometry and material parameters of monopile connection based on the ultimate and fatigue capacities according to DNV standards. Next, optimization is conducted to minimize the total mass and resulted in 30% weight reduction and the optimum geometry and material properties of the monopile substructure of the fixed offshore wind turbine.

• 한국유체기계학회 논문집
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• 제17권5호
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• pp.78-82
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• 2014

This paper describes a brief aerodynamic design procedure of multi-stage axial turbine. The design procedure was established including one dimensional scratch design, through flow analysis with empirical correlations, two dimensional airfoil design and three dimensional airfoil stacking. Detailed aerodynamic performance assessment was done with full three dimensional CFD method at the design and off design conditions to construct turbine performance map. With the present method, aerodynamic design procedure of 1st and 2nd stages of high pressure turbine for 10,000lbf class turbofan engine was introduced.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.670-675
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• 2001

This paper describes aerodynamic preliminary design performance prediction and flow analysis for turbine of the marine middle engine turbocharger. The performance characteristics of turbocharger turbine are investigated at various operating conditions using mass flow rate and computational flow analysis for rotor and nozzle at design point are performed. Preliminary design results are performed by applying mean line and radial equilibrium theory. Performance prediction and flow analysis results show good agreement with experiments. From 3 dimensional flow analysis result, efficiency is 0.6% greater than design point. Therefore, this design approach is useful for preliminary design, and helps to increase the design capability for optimized rotor blade.

• 한국기계연구소 소보
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• 통권14호
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• pp.111-119
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• 1985

A review on the design analysis of an axial-flow turbine is presented. Followed by a brief introduction to the fundamentals on an axial-flow turbine, a design procedure is described with a sample design of one for a small turbo-jet engine. Design procedure is composed of two parts: one-dimensional analysis of three-dimensional effects based on radial equilibrium theory. The method described herein is so simple and rapid that it can be applied to the preliminary design analysis of turbo-machinery equipped with axial-flow turbines.