• Journal of IKEEE
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• v.11 no.4
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• pp.358-363
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• 2007

This paper presents a floating point unit(FPU) with 3 stages for a 3D graphics shader engine. It targeted to accelerate 3D graphics in portable device environments. In order to design a balanced architecture for a shader engine, we analyzed shader assembly instructions and estimated the performance of FPU with the method we propose. The proposed unit handles 4-dimensional data through separated two paths that are lead to general operation module and special function module. The proposed FPU is compiled as a form of the cascade FPU with 3 stages to efficiently handle a matrix operation with relatively low hardware overhead. Except some complex instructions that are executed using macro instructions, all instructions complete an operation in a single instruction cycle at 100MHz frequency. A special function module performs all operations in a single clock cycle using the Newton Raphson method with the look-up table.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.79-84
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• 2010

The supply system module of the liquid rocket engine has been developed, which consists of the various supply system components such as pipes, orifices, elbows, bellows, valves and flanges. This module can size the components and calculate pressure drops between them. For the assembly of the supply system components, the supply system module can evaluate the number of the components, total pressure drop, outlet pressure and total system weight.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.5
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• pp.104-111
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• 2009

A ship engine operator should compensate the crankshaft assembly of ship engine after inspecting crankshaft deflection error in the crank throw regularly to avoid engine vibration and abrasions. In the previous method, the operator enters the bed plate and measures crankshaft deflection using dial gauge on rotating crankshaft manually. However, this method can cause dangerous situation to the operator as well as uncomfortable in an inferior environment. In order to solve the problems, this paper studies the method which makes the operator measure the error outside of the bed plate. In this paper, it is suggested that BlueTooth wireless communication transfers the error data to the outer standing operator with digitalized crankshaft deflection inspection device developed in this paper. So, the wireless measurement system is developed and applied to a medium-speed marine engine through size-miniaturization. After applying test, the developed inspection device showed that it provides much safe and ease inspection method. Furthermore, in the result, the measuring accuracy is more improved.

• Tribology and Lubricants
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• v.24 no.1
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• pp.21-26
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• 2008

A pin bush bearing is one of the most important element in the piston engine which is joined a piston to a connecting rod. A pin bush is suffered by heat and changeable repeat loads, which are come from the explosive gas heat and pressures during a reciprocating stroke. Therefore, a tribological behavior of pin bush bearings is very severe compared to other parts of a piston assembly. To keep a stable operation of pin bush bearings effectively, it would be satisfied with proper oil film strength for severe operating conditions and durability, which are strongly related to the oil film thickness, oil film pressure, and a friction loss power. The computed results show that the viscosity of engine oils slightly affects to the minimum oil film thickness and oil film pressure distribution, but is an influential parameter on a total friction loss power. Thus the low viscosity engine oils for an increased operation condition should select a high level of base oil and add a viscosity index improver as an oil film additive.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.12
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• pp.1639-1645
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• 2002

Micro engine that includes Micro scale combustor is fabricated. Design target was focused on the observation of combustion driven actuation in MEMS scale. Combustor design parameters are somewhat less than the size recommended by feasibility test. The engine structure is fabricated by isotropic etching of the photosensitive glass wafers. Electrode formed by electroplating of the Nickel. Photosensitive glass can be etched isotropically with almost vertical angle. Bonding and assembly of structured photosensitive glass wafer form the engine. Combustor size was determined to be 1 mm scale. Movable piston is engraved inside the wafer. Ignition was done by nickel spark plug which was electroplated with thickness of 40 ${\mu}{\textrm}{m}$. The wafers were bonded by epoxy that resists high temperature. In firing test due to the bonding method and design tolerance pressure buildup by reaction was not confirmed. But ignition, flame propagation and actuation of micro structure from the reaction was observed. From the result basement of design and fabrication technology was obtained.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.107-118
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• 2010

Automotive manufacturing is a complex task that requires the production and assembly of thousands of different components or parts. The engine and the transmission are the major components that constitute a power train system. Although manufacturing processes of an engine are similar, the layouts of the manufacturing lines are different from factory to factory. It is due to the different design concept that how to combine the serial and parallel structures. In this paper, three engine lines of different factories are introduced, and the simulation technology is used to make the performance analysis for different design concepts.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.291-297
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• 2008

The launch of the COMS by using Ariane-5 launch vehicle is introduced. First, the COMS is introduced briefly, and then, the Ariane-5 launch vehicle is introduced including detail description of the improvement of Vulcain-1 engine of Ariane-5G to Vulcain-2 engine of Ariane-5ECA for 20% increase of thrust. Then, the launch process of the COMS is introduced. The COMS will be launched from the Guiana Space Center in Kourou, French Guiana. After the final check at PPF the COMS is transferred to HPF in the same building for fueling, and it is integrated to the launch vehicle adaptor at HPF, too. Then, this assembly is transferred to Final Assembly Building. After the satellites to be launched together are integrated to the launch vehicle on the launch table in the Final Assembly Building, the launch table loaded with the launch vehicle is moved to the launch pad for launch. The events during the launch vehicle flight is also introduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.687-692
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• 2016

When turbochargers are applied to engines, the temperature of the engine becomes high, making the cooling of pistons very important. To solve this problem, an oil jet is used. The oil jet provides oil to the underside of piston for cooling. When an oil jet is used, oil pump size-up and oil cooler are needed because of the increased oil flow rate and higher oil temperature. On the other hand, these increase the friction torque of the engine. This study examined how much the friction torque of an engine increases by an oil jet, oil cooler, and oil pump size-up. In addition, the proportions of the friction torque of the engine increased by each part were measured by changing the engine assembly condition. At low speed, the oil pump and oil cooler had a larger effect on the friction torque than the other factors. At high speed, oil cooler had a larger effect than the other factors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4093-4099
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• 2014

In this study, the thermal-structural behavior of the combustor assembly of 200 kW micro gas turbine system was performed. The typical combustor assembly consists of a Liner, Inner & Outer Case, Burner and Nozzle ring, etc. There are some gaps and friction elements between the components to compensate for the different thermal expansions of various components. Therefore, the developed finite element model includes nonlinear elements. The boundary support conditions of the combustor assembly significantly affect the stress distribution due to the high temperature gradient. This paper deals with parametric studies to quantitatively determine the effects of the variation of the support conditions on the stress distribution and deformation of various components of combustor assembly. These results may be useful for the design of the combustor assembly.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.139-149
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• 1994

A numerical simulation of unsteady axisymmetric turbulent flow was performed for a reciprocating engine including port/valve assembly. The governing equations based on a nonorthogonal coordinate formulation with Cartesian velocity components were used and discretised by the finite volume method with non-staggered variable arrangements. The modified $\kappa-\xi$. turbulence model which included the effect of compressibility was used. The results of twodimensional transient calculation for the axisymmetric configuration were compared with the experimental data. Although slightly low rms velocity was predicted compared to the experimental data, predicted velocity distributions at the valve exit and in-cylinder region showed good agreements with the experimental data. The flow at the valve exit was separated at the same valve lift position with the experimental data. Two vortices incylinder region were generated during the initial intake process. The clockwise main vortex became strong and moved upward to the top wall. The counter-clockwise second vortex became weak and stick to the upper left corner of the cylinder. After middle intake process, new vortex adjacent to upper cylinder wall appeared by the piston motion and therefore, the in-cylinder flow was formed into three vortices. The cylinder pressure just before bottom dead center of piston was higher than inlet pressure and then the reverse flow occured at the valve exit. The in-cylinder flow characteristics were strongly dependent on piston motion, but insensitive to valve motion.