System Analysis of a Gas Generator Cycle Rocket Engine

Cho, Won Kook,Kim, Chun IL The Society for Aerospace System Engineering 2019 International Journal of Aerospace System Engineer Vol.6 No.2

A system analysis program has been developed for a gas generator cycle liquid rocket engine of 30 ton class. Numerical models have been proposed for a combustor, a turbopump, a gas generator and pressure drop through a regenerative cooling system. Numerical algorithm has been validated by comparing with the published data of MC-1. The major source of error is not the numerical algorithm but the imperfect performance models of subsystems. So the precision of the program can be improved by revising the performance models using experimental data. The sea level specific impulse and vacuum specific impulse have been demonstrated for a 30 ton class gas generator engine. The optimal condition of combustor pressure and mixture ratio for specific impulse which is a typical characteristic of a gas generator cycle engine has been illustrated.

Development of Operating Program for EECU Test Bench

Kang, Myoungcheol,Kho, Seonghee,Ki, Jayoung The Society for Aerospace System Engineering 2014 International Journal of Aerospace System Engineer Vol.1 No.1

This study presents technical description of the operating program development that operates the test bench for functional test of EECU. The test bench is capable of testing, simulation and adjustment of the EECU software using the operating program. The test bench is for the Development Project of the EECU platform for FADEC system. The operating program is consists of 3 modules which are the test bench operating module, cockpit simulator module and SILS module. The operating module mainly carries out the EECU test with manual operation and operating scenarios. Also that record and process the test data. The cockpit simulator module is capable of implementation of virtual cockpit control input and engine status display. The SILS module can simulate engine and EECU operation in software environment.

Turbine Performance Experiments for the Turbopump of a Liquid Rocket Engine

Lee, Hanggi,Shin, Juhyun,Jeong, Eunhwan,Choi, Changho The Society for Aerospace System Engineering 2016 International Journal of Aerospace System Engineer Vol.3 No.1

This paper highlights the performance of an impulse turbine which is a part of turbopump in a liquid rocket first stage engine. The turbopump, currently under development at Korea Aerospace Research Institute, has an impulse type turbine with 12 nozzles and a single rotor. The impulse turbine can archive high specific power with the low gas flow rates. The supersonic impulse turbine with a single rotor can make a simple structure. High-pressure gases are converted into the dynamic energy with flows through the 12 nozzles and drive the rotor to make the power for the pumps. The turbine test was performed in the high-pressured turbine test facility with air gas instead of burned gas. A hydraulic dynamometer was used to absorb the power from the turbine and control the rotational speed and torque. The test points were at several pressure ratios with 7 different rotational speeds. Results showed the efficiency was highest at the design pressure ratio. The efficiency was insensitive to the pressure ratio variation than the rotational speed. It was a typical characteristic in an impulse turbine.

Comparison of Effectiveness for Performance Tuning of Liquid Rocket Engine

Cho, Won Kook,Kim, Chun Il The Society for Aerospace System Engineering 2018 International Journal of Aerospace System Engineer Vol.5 No.2

An analysis has been made on the performance variation due to pressure drop change at propellant supply pipes of liquid rocket engine. The objective is to compare the effectiveness of control variables to tune the liquid rocket engine performance. The mode analysis program has been used to estimate the engine performance for different modes which is realized by controlling the flow rate of propellant. The oxidizer of combustion chamber, the fuel of combustion chamber, the oxidizer of gas generator and the fuel of gas generator are the independent variables to control engine thrust, engine mixture ratio and temperature of gas generator product gas. The analysis program is validated by comparing with the powerpack test results. The error range of compared variables is order of 4%. After comparison of tuning effectiveness it is turned out that the pressure drop at oxidizer pipe of gas generator and pressure drop at combustion chamber fuel pipe and the pressure drop at the fuel pipe of gas generator can effectively tune the thrust of engine, mixture ratio of engine and temperature of product gas from gas generator respectively.

Transient Analysis of Self-Powered Energy-Harvesting using Bond-Graph

Makihara, Kanjuro,Shigeta, Daisuke,Fujita, Yoshiyuki,Yamamoto, Yuta The Society for Aerospace System Engineering 2015 International Journal of Aerospace System Engineer Vol.2 No.1

The transient phenomenon of self-powered energy-harvesting is assessed using a bond-graph method. The bond-graph is an energy-based approach to describing physical-dynamic systems. It shows power flow graphically, which helps us understand the behavior of complicated systems in simple terms. Because energy-harvesting involves conversion of power in mechanical form to the electrical one, the bond-graph is a good tool to analyze this power flow. Although the bond-graph method can be used to calculate the dynamics of combining mechanical and electrical systems simultaneously, it has not been used for harvesting analysis. We demonstrate the usability and versatility of bond-graph for not only steady analysis but also transient analysis of harvesting.

Application of BIM on Drawing Verification of Firefighting

Chang, Ya-Chun,Shr, Jin-Fang,Huang, Xuan-Chao The Society for Aerospace System Engineering 2015 International Journal of Aerospace System Engineer Vol.2 No.2

In general, most of the function and using of building is for single purpose. However, current buildings combine several functions that causes a lot of problems not on firefighting only but also on environment engineering. Because of hard integration on different fields that causes a lot of conflict. That wastes cost and time. That also threaten the safety of firefighting. This search focuses on the drawing verification and field inspection on firefighting. These two items both remain paper work. To complete the current work, it needs to bring a great amount of drawing papers in the field. By BIM, integrated data can be extracted. It makes the drawing verification and field inspection easier and increases the efficiency. That is the main point of this research.

Structural Design of Composite Blade and Tower for Small Wind Turbine System

Jang, Mingi,Lee, Sanggyu,Park, Gwanmun,Park, Hyunbum The Society for Aerospace System Engineering 2015 International Journal of Aerospace System Engineer Vol.2 No.1

This work is to propose a structural design and analysis procedure for development of the low noise 1kW class small wind turbine system which will be applicable to relatively low speed region like Korea and for the domestic use. The proposed structural configuration has a sandwich composite structure with the E-glass/Epoxy face sheets and the Urethane foam core for lightness, structural stability, low manufacturing cost and easy manufacturing process. Structural analysis including load cases, stress, deformation, buckling, vibration and fatigue life was performed using the Finite Element Method, the load spectrum analysis and Miner rule. In order to evaluate the designed structure, the structural test was carried out and its test results were compared with the estimated results. Moreover Investigation on structural safety of tower was verified through structural analysis by FEM.

The Development Progress of Korean Aviation Industry and its Investment Strategy Based on the Evidence and the 4th Industrial Revolution

Kim, Jongbum The Society for Aerospace System Engineering 2018 International Journal of Aerospace System Engineer Vol.5 No.2

This study examines the history of Korean aviation industry and presents the investment strategy based on the evidence and the 4th industrial revolution. Looking at the evolution of the Korean aviation industry and its technological development will be a great help to support industrial and technological innovation in the future. The modern aviation industry is divided into stages of development, focusing on maintenance of equipment introduced in advanced countries, localization through license assembly, production of products based on technology, and international joint development. The development of aeronautics technology has been progressing towards a general improvement of economic efficiency, aircraft safety efficiency through environmental-friendliness, unmanned operation, and downsizing. The Korea Aerospace Research Institute has secured key technologies through development of several aircrafts such as Experimental Aircraft Kachi, EXPO Unmanned Airship, Twin-engine Composite Aircraft, Canard Aircraft, Multi-Purpose Stratosphere unmanned-airship, Medium Aerostats, Smart UAV, Surion, EAV-2H, KC-100, and OPV. The development strategy is discussed at the level of the evidence-based investment strategy that is currently being discussed, and so the investment priorities in aircraft is high. Current drone usage and development direction are not only producing parts using 3D printer, but also autonomous flight, communication (IoT, 5G), information processing (big data, machine learning). Therefore, the aviation industry is expected to lead the fourth industrial revolution.

Dynamical Analysis and Design of Bearingless Rotor Flexbeam

Shi, Weixing,Wang, Jidong The Society for Aerospace System Engineering 2015 International Journal of Aerospace System Engineer Vol.2 No.1

In helicopter bearingless rotor design, the flexbeam is the key component of rotor system, which plays an importantrole in the blade flapping, lead-lag movement, torsion, and load transfer. Flexbeam must have the minimum torsion stiffness with enough tension strength. In this paper, we first investigated the torsion stiffness of different cross section configurations of the flexbeam through some simple experiments. Then we analyzed a rotor's dynamical characteristics with finite element method and got the rotor's fan plot. After that, we studied the relationship between the frequency changes with the spanwise distribution of mass and stiffness in bearingless rotor. Finally, we analyzed the influence of the flexbeam on dynamical characteristics of the bearingless rotor system, and completed the design of this type of rotor flexbeam.

Performance Analysis Model for Flap Actuation System using MATLAB/Simulink

Cho, Hyunjun,Joo, Choonshik,Kim, Kilyeong,Park, Sangjoon The Society for Aerospace System Engineering 2017 International Journal of Aerospace System Engineer Vol.4 No.1

In this paper, we present some results on performance analysis for flap actuation system of aircraft. For this, by utilizing MATLAB/Simulink solution, which is widely used physical model-based design tool, we particularly construct the architecture of the analysis model consisting of the main three phases: 1)commanding and outer-controlling the flap angle through flight control computer; 2)generating hydraulic/mechanical power through control module and power drive unit; 3)transmitting torque and actuating the flap through torque tube and rotary geared actuators. For mimicking the motion of the actual flap, we apply each mechanical component, which is already being used in actual aircraft, to our performance analysis model so that it guarantees the congruency of the simulation results. That is, we reflect the actual specifications of flap hardware and software as parameters of the model. Finally, simulation results are presented to illustrate the model.