• Journal of Biosystems Engineering
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• 제34권6호
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• pp.470-475
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• 2009

This study was performed to present the diagnosis basis of cooling performance deficiency according to air quantity included in refrigerant of air-conditioner by detecting the temperatures and pressures of refrigerant pipeline. The car air-conditioner of SONATA III (Hyundai motor Co., Korea) was tested by maximum cooling condition at 1500 rpm of engine speed in the room with controlled air condition at $33\sim35^{\circ}C$ and 55~57% RH. Measured variables were temperature differences between inlet and outlet pipe surface of the compressor (Tcom), condenser (Tcon), receive dryer (Trec) and evaporator (Teva), and high pressure (HP) and low pressure (LP) in the refrigerant pipeline, and temperature difference (Tcoo) between inlet and outlet air of the cooling vent of evaporator. Control variables were the refrigerant charging weight and the vacuum degree in the refrigerant pipeline before charging refrigerant. From the test, it was represented that the measuring values of (Tcom), LP and (Tcoo) were enabled to make the diagnosis of cooling performance deficiency according to quantity included in refrigerant of air-conditioner. The ranges of Tcom, LP and Tcoo to make the diagnosis of cooling performance deficiency were respectively less than $55^{\circ}C$, more than 166.7 kPa-g(1.7 kgf/$cm^2$) and less than $13.7^{\circ}C$. In the case of using only external sensors and the condition under the normal performances of air conditioner, it was considered that the ranges of LP and Tcoo to make the diagnosis of cooling performance deficiency were respectively more than 166.7 Pa and less than $12^{\circ}C$.

• 대한조선학회논문집
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• 제54권6호
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• pp.470-475
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• 2017

Since the intake air of gas turbine engine of marine purpose contains water particles, inertial separator for separating the air and water particles are provided. Saw type and wave type separator are now used to separate inflow water particle from the gas. In this paper, the design parameters of saw type separator are studied by numerical simulations. Using the commercial CFD program, Star-CCM+, Lagrangian-Eulerian method was used to perform the analysis of two phase flow of the mist in the air. This method solves Reynolds-Averaged Navier-Stokes equations in Eulerian framework for the continuous phase, while solves equation of motion for individual particles in Lagrangian framework. Lagrangian multiphase method was applied to monitor the particles of different sizes and shapes and to verify collision between particles by chasing particles. Water particles were injected through injectors located at the inlet of the separator and escape mode was used which assumes that the particles attached on the surface of inertial separator were removed from the simulation, effectively escaping the solution domain. Through the numerical computations with the inlet condition of constant water particle size in the wetness fraction of 85%, efficiency of eliminating the water particle and the pressure drop between the inlet and outlet were examined.

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.31-35
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• 2013

Unsteady fluid dynamics analysis of flow characteristics inside a Metal DPF system is done using a commercial CAE software, CFD-ACE+. The time profiles of both temperature and pressure of exhaust gas are given as initial conditions. It was found that the position of connecting pipes and the numbering of exhaust gases did not affect the flow uniformity. The presence of a DPF resulted in the significant flow nonuniformity effect on the flow characteristics at the inlet of the DPF. Present results can be applied to the selection of optimal geometry that produces uniform flow characteristics inside a DPF system.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.112-117
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• 2007

With the Euro-4 regulation coming into effect, the domestic car industry is forced to look for newer options to reduce NOX in the exhaust. EGR(Exhaust Gas Recirculation) Cooler is an effective method for the reduction of NOX form a diesel engine. High efficiency, low pressure loss and compactness are desirable features of an EGR Cooler. The cooling performance of EGR depends on the shape of tubes and the location of the entrance and exit. This paper reports the computational work conducted to estimate the performance of EGR cooler with three different cross section tubes and a triangular spiral tube. Three dimensional computation results show that the triangular tube is more effective than circular and rectangular tube. The most effective geometry is a triangular spiral tube with offset inlet and outlet locations.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제26회 춘계학술대회논문집
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• pp.351-354
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• 2006

PW206C 터보샤프트 엔진을 장착한 스마트무인기 연료시스템의 연료공급계통과 연료이송계통의 설계와 성능분석을 수행하였다. 연료공급계통은 엔진 연료입구에서의 최소압력과 최대압력 조건에 대한 성능분석을 통하여 엔진의 요구조건을 만족함을 확인하였다. 연료탱크간의 연료이송을 담당하는 제트펌프의 설계조건으로 비행체의 최대수평가속비행에서 ESDU와 Flowmaster 코드를 이용한 설계와 성능해석을 수행하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.596-599
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• 1997

In this study, the flow control system with shape memory alloy in jet engine inlet was suggested to adjust the shock boundary layer interact~on for supersonic flight system. It consisted of the flap with shape memory alloy, spar with steel, and fixing device with aluminum alloy. The advantages of itself are a simple configuration, a passive air circulation by using the flap deflection due to pressure difference, and no need to be required the auxiliary devices. Finite element analysis was conducted to predict the thenno-mechanical behavlor of the flap system with shape memory alloy. The user-defined subroutine UMAT was implemented with ABAQUS to accon~modate the thermo-mechanical constitutive relation of shape memory alloy.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제20회 춘계학술대회 논문집
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• pp.189-192
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• 2003

추진제 주입 압력 350 psi 에서 0.95 lbf 의 정상상태 공칭추력을 내는 단일액체추진제 하이드라진 추력기의 검증을 위한 성능 요구조건과 시험결과를 요약한다. 성능특성은 정상상태 및 펄스 모우드 연소상태에서의 추력 거동으로 제시되고 지상연소시험과정이 간략히 소개된다.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.181-186
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• 1999

The objective of present work is to investigate the performance characteristics of three-lobe Roots type supercharger for the applications of low-compression and high-expansion ration gasoline engine. A performance test was conducted to obtain the drive power, volumetric efficiency, adiabatic efficiency and the influence of performance factors of supercharger . In order to analyze the supercharging characteristics, the experiments are made on operating parameters such as the supercharger speed, pressure ration and inlet temperature on the supercharging performance of the Roots type supercharger . Based on experimental results, the drive power and flow rate of supercharger increased with supercharger speed.

• 한국자동차공학회논문집
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• 제24권1호
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• pp.74-81
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• 2016

The aim of this study was to find the initial design value of turbine blade for electrical type turbocompound system generating 10 kW. Turbocompound is one of the waste heat recovery system applying to internal combustion engine to recover exhaust gas energy that was about 30 % of total input energy. To design the turbine blade, 1-D mean line flow model was used. Exhaust gas temperature, pressure, flow rate and turbine rotating speed was fixed as primary boundary conditions. The velocity triangles was defined and used to determine the rotor inlet radius and width, the rotor outlet radius at shroud and radius at hub, the rotor flow angles and the number of blades.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제23회 추계학술대회 논문집
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• pp.79-82
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• 2004

추진제 공급계는 발사체에 탑재될 엔진에 추진제를 요구조건 (유량, 온도, 압력 등)에 맞게 공급하는 시스템을 말한다. 본 시험 설비는 추진제 공급 시스템 개발시 주요 구성기술인 가압 시스템 개발, 탱크 내 프로세스 개발, 추진제 배관 시스템 개발을 위해 구축되고 있다. 본 논문에서는 현재 항 우연 내에 구축중인 추진제 공급 시험 설비를 소개한다.