• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.95-99
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• 2004

The developing Smart UAV in KARI supposes high speed flight as like a conventional plane, as well as vertical takeoff and landing as like a helicopter. Therefore, the air intake system should be designed to provide the sufficient air flow to the engine and the maximum possible total pressure recovery at the engine intake screen over a wide range of flight conditions. For this purpose, we designed the intake system using a pilot type intake model and plenum chamber In this paper, we designed the intake model and analyzed the performance of designed intake system using the general-purpose commercial CFD code, CFD-ACE+ For 3-D calculation, we generated mesh using the unstructured gird and used $\kappa-\epsilon$ turbulence model. The analysis results of the total pressure variation and the velocity distribution was illustrated in this paper. The pressure recovery and distortion coefficient at a plane coincident with the compressor inlet were calculated and streamline variation through the intake system was investigated at the worst condition as well as the standard flight condition.

• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.25-31
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• 2012

A computational study on the improvement of the pressure loss of intake system, which is located at engine manifold of the combat vehicle, has been conducted using a finite-volume-based, Reynolds-Averaged Navier-Stokes (RANS) solver. The computational result of the pressure loss through the air cleaner is in good agreement with equivalent experimental data. A parametric study was done for improving of the pressure loss of intake system over the baseline case. The effects of five primary parameters such as the height of inlet, the width of interconnection pipe, the shape of drain chamber and the diameter of filter housing were considered in this study. Consequently, this computational investigation can contribute to finding an optimal guideline for the idea of improvement in the pressure loss of intake system.

• Journal of Mechanical Science and Technology
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• v.18 no.2
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• pp.286-293
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• 2004

The air fuel ratios of current gasoline engines are almost controlled by several air flow meters. When CVVT (Continuous Variable Valve Timing) is applied to a gasoline engine for higher engine performance, the MAP (Manifold Absolute Pressure) sensor is difficult to follow the instantaneous air fuel ratio due to the valve timing effect. Therefore, a HFM (Hot Film Flow Meter) is widely used for measuring intake air flow in this case. However, the HFMs are incapable of indicating to reverse flow, the oscillation of intake air flow has an negative effect on the precision of the HFM. Consequently, the various duct configurations in front of the air flow sensor affect the precision of HFM sensitivity. This paper mainly focused on the analysis of the reverse flow, flow fluctuation in throttle upstream and the geometry of intake system which influence the HFM measurement.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.11-15
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• 2011

This study investigated the symptoms of the a reduction in output while driving on the road, or increasing of fumer out exhaust gas on inclined road while working air-conditioner in summer. Notice how the experiment in 2010, the Ministry of Environment(Chapter No. 2010-46), and how the vehicle emissions inspection was carried out. 2500cc Diesel cars used in the study were used and compare to output of engine, exhaust gas, inhalation temperature measurement Inhalation of cold air has not been supplied to all agencies when comparing the results when cold air intake temperature of the supply air-conditioning switch range control from 1 to 4, the temperature drops $98^{\circ}C$ to $78^{\circ}C$. At the momentum of switch level 4, output from 63ps to 66ps after the connection has increased 9.6 percent, the highest concentration of exhaust emissions were reduced by 42.8%. This research can contribute in part to the reduction of exhaust directly supply into the cooling air intake line, doing the output of diesel cars in the summer. In addition, construction equipment and machinery that are currently being used excluding the engine's intercooler cooling of the supply line via a separate output in the summer and help reduce exhaust emissions is expected.

• Aerospace Engineering and Technology
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• v.3 no.2
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• pp.197-207
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• 2004

The developing Smart UAV in KARI supposes high speed flight as like a conventional plane, as well as vertical takeoff and landing as like a helicopter. Therefore, the air intake system should be designed to provide the sufficient air flow to the engine and the maximum possible total pressure recovery at the engine intake screen over a wide range of flight conditions. For this purpose, we designed the intake system using a pitor type intake model and plenum chamber. In this paper, we designed the intake model and analyzed the performance of designed intake system using the general-purpose commercial CFD code, CFD-ACE+. The analysis results of the total pressure variation and the velocity distribution were illustrated in this paper. The pressure recovery and distortion coefficient at a plane coincident with the compressor inlet were calculated and streamline variation through the intake system was investigated at the worst flight condition as well as the standard flight condition.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.6
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• pp.1921-1930
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• 1996

To design an optimum engine intake system, a flow model for the intake manifold was developed by the finite difference method. The flow in the intake manifold was one-dimensional, and the finite difference equations were derived from governing equations of flow, continuity, momentum and energy. The thermodynamic properties of the cylinder were found by the first law of thermodynamics, and the boundary conditions were formulated using steady flow model. By comparing the calculated results with experimental data, the appropriate boundary conditions and convergence limits for the flow model were established. From this model, the optimum manifold lengths at different engine operating conditions were investigated. The optimum manifold length became shorter when the engine speeds were increased. The effect of intake valve timings on inlet air mass was also studied by this model. Advancing intake valve opening decreased inlet air mass slightly, and the optimum intake valve closing was found. The difference in inlet air mass between cylinders was very small in this engine.

• Journal of Drive and Control
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• v.10 no.2
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• pp.23-29
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• 2013

The excavator is used in a variety of construction environments. There are many kinds of risk like falling rocks or harmful dust. The excavator cabin protects the operator not only from these harmful environments but also provides a comfortable working environment. By the way, the excavator cabin consumes a lot of energy for cabin air conditioner. For this reason, the research is required to reduce energy consumption. This study suggests the air conditioning system for excavator using forced exhaust. First, the forced exhaust system simulated by AMESim tool and surveyed the applicability. Using AMESim simulation, it was investigated the effect of cabin inside temperature by intake flow rate and intake air temperature. The experiment executed using the 1.5 ton excavator and field tested according to the intake flow rate. Finally, verified the applicability on the air conditioning system for excavator using forced exhaust.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.92-101
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• 1996

In a gasoline engine, the characteristics of air flow is very important not only for the design of the intake system geometry bout also for the accurate measurement of the induction air mass. In this study, an air flow rate measurement of the induction air mass. In this study, an air flow rate measurement was conducted by using the hot wire flow meter at the upstream of the intake port and the throttle. At the upstream of the throttle, the overshoot phenomena of the air flow rate by fast throttle opening were analyzed with choked flow. At the upstream of the intake port, the cylinder variation of the air flow rate and the difference between fast throttle opening and closing were showed during the unsteady state by the throttle step change. The results of this study can be used for the design of the throttle valve geometry and cylinder by cylinder control.

• Korean Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.168-176
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• 1998

This paper deals with an application on the mould machining of air intake hose product by using 3-dimensional parametric modeling techniques. The detailed domain is the 3-dimensional product with similar shapes and different sizes which needs too much working time for preparation of modeling or machining due to making a trial and errors repeatedly. Decision making rules for selection of modeling order and technique, and for calculation of cutting conditions, and for determination of sequence and method concerning machining operations are required by interview of expert engineers in the field. The developed expert system of modeling and machining is programmed by using a user programming language under the CAD/CAM software of the Personal Designer. The developed system that aids a mould engineer who is working in the modeling and machining section which deal with air intake hose product provides strong and useful capabilities.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.81-85
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• 2022

In this study, we conducted a structural design and analysis of air intake of aircraft engine using composite materials. First, an investigation on structural design requirement of target structure was carried out. The distributed pressure load and acceleration condition was applied to structural design. To evaluate the structural design result, finite element analysis was carried out. The stress, deflection and buckling analysis for structural safety evaluation was performed. Finally, it was confirmed that the air intake through structural analysis is safety.