• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.1
• /
• pp.1-7
• /
• 2013

An aerodynamic rig test of a radial turbine for an auxiliary power unit (APU) was performed at a high-temperature turbine test facility at the Korea Aerospace Research Institute. The pressure ratio, Mach number, and flow coefficient in the rig test are the same as those under normal engine operation conditions. The design pressure ratio is 3.096, design test speed is 34909 rpm, and turbine inlet temperature is $160^{\circ}C$. The turbine has airfoil-type nozzles, and the diameter of the turbine wheel is 175.74 mm. The turbine map is experimentally measured, and the detailed flow at the turbine inlet is measured. The pressure distribution in the nozzle at both the hub and the shroud sides and the pressure distribution along the shroud casing of the turbine wheel were measured, and this confirmed that the expansion process in the turbine wheel is acceptable.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.11 no.4
• /
• pp.59-66
• /
• 2007

In this paper, experimental investigation results of the effect of partial admission ratio on the performance of axial turbine was presented. A supersonic impulse turbine of gas generator cycle liquid rocket engine turbopump was used for the test. for experimental purpose, a nozzle block, in which total 14 number of axi-symmetric convergent-divergent nozzles are arranged circumferentially, was designed and manufactured. Partial admission ratio was controlled by changing the number of active nozzles. High pressure air was used as working medium for the test. The experimental result revealed that the performance of the supersonic impulse turbine does not much affected by the partial admission ratio for supersonic impulse turbine.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.14 no.3
• /
• pp.30-38
• /
• 2010

Experiments were performed to investigate the flow characteristics of a partial admission supersonic turbine depending on the relative positions of nozzle and cascade. The flow was visualized by a Schlieren system. The static pressures at the turbine cascade inlet, passage and outlet were measured by pressure transducers. Highly complicated flow patterns including shocks, nozzle-cascade interaction and shock boundary layer interactions of the supersonic turbine were observed by the experiments. And the flow characteristics in the supersonic turbine as the relative positions were observed.

• Journal of Aerospace System Engineering
• /
• v.11 no.1
• /
• pp.8-13
• /
• 2017

This study was performed to evaluate the turbine performance of a turbopump in the third stage engine of the Korea Space Launch Vehicle-II. The turbine is a supersonic impulse type with a single rotor. One nozzle is for starting and four remaining nozzles are for steady operation. A similarity test was carried out in the high air test facilities at the Korea Aerospace Research Institute. Test results showed that turbine efficiency changed much more from rotational speed variations than by pressure ratio variations. These results showed characteristics similar to other supersonic impulse turbines.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.7
• /
• pp.639-646
• /
• 2014

The comparative analysis of near-wall treatment methods that affect the prediction of heat transfer over the gas turbine nozzle guide vane were presented. To achieve this objective, wall-function and low Reynolds number methods, and the transition model were applied and simulated using NASA's C3X turbine vane. The predicted turbine vane surface pressure distribution data using the near-wall treatment methods were found to be in close agreement with experimental data. However, the predicted vane metal temperature and heat transfer coefficient displayed significant differences. Overall, the low Reynolds method and transition model did not offer specific advantages in the prediction of temperature and heat transfer than did the wall-function method. The Reynolds stress model used along with the wall-function method resulted in a relatively high accuracy of prediction of the vane metal temperature and heat transfer coefficient.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.15 no.1
• /
• pp.19-28
• /
• 2011

As a preview study, present research analysed the performance characteristics of a velocity compound supersonic impulse turbine with the rotor overlaps before adapting the overlap has the best turbine performance. This research was conducted for the turbine with square cross-section nozzles instead of axisymmetric nozzles and wrap around nozzles. Through 3-dimensional flow analysis for the turbine by a commercial flow analysis package, tip overlap case was more effective to improve the turbine performance than case hub overlap, and overlap case applied the hub and tip of the rotor had the largest improvement for the turbine performance in the cases. In case of overlap for the 2nd stage rotor, improvement of the turbine performance was not visibly large. Because, generated power in the 2nd stage is 22~23% of whole generated turbine power.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.41 no.10
• /
• pp.685-691
• /
• 2017

In this study, the influence of mass flow rate on the isentropic efficiency of the steam turbine nozzle stage is investigated. A realistic three-dimensional numerical model, which is based on the compressible Navier-Stokes equations, is developed for the steam phase. The comprehensive conservation laws and a kinetic model for steam are investigated. With two different models for the three-dimensional geometry of the nozzle stage, the pressure and temperature distributions, velocity, Mach number. and Markov energy loss coefficient are calculated. A maximum efficiency of 96.66％ is found at a mass flow rate of 0.9 kg/s in model A. In model B, a maximum efficiency of 97.32％ is found at a rate of 1.6 kg/s. It is determined that the isentropic nozzle efficiency increases as the Markov energy loss coefficient decreases through a nearly linear relationship.

• Clean Technology
• /
• v.9 no.4
• /
• pp.163-168
• /
• 2003

Basic concepts and procedures for designing air turbine and atomizing disk, which require core technologies, of rotary atomizer were established. Experimental data agreed well with the computational fluid dynamics analysis results. The rotary atomizer RPM was varied remarkably for various air turbine and atomizing disk types. Experimentally, the atomizer with $20^{\circ}$, slope-contraction and 2 nozzle air turbine has shown the most desirable performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.542-545
• /
• 2009

In this study, the effect of turbine geometry on the overall performance of a gas turbine was investigated by computational fluid dynamics. Overall engine performance was predicted through a full engine simulation program which can predict the interactions of the compressor, the combustor and the turbine. The compressor and the turbine analysis code solves 2D and 3D Navier-Stokes equations respectively. The chemical equilibrium code was applied to simulate the combustor. The computations were performed for two different shapes of turbine nozzle. The nozzle shapes adopted a baseline blade and a blade with fillet.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.33 no.3
• /
• pp.234-240
• /
• 1997

터보 챠저의 반동도와 터빈 노즐유량의 변화를 행하여 엔진의 성능을 향상시킬 수 있었다. 터빈의 에너지 손실과 그 영향을 미치는 반동도 및 터빈 입구의 유로의 변화, 그리고 블레이드에서 역 유동에 대한 개선 조건도 제시하였다.