缸內燃油噴射(gasoline direct injection, GDI)技術Mitsubishi Motor 於1995發展出來之後廣泛使用於汽車及機車引擎，此技術擁有降低油耗、減少汙染物之排放量、增加燃燒效率，並且能提升引擎整體性能輸出。而缸內燃油直噴之技術需搭配缸內氣流之滾轉與旋轉之運動達到所需之空氣與燃料混合型態(homogeneous或 stratified charge)，之後進入點火燃燒，本研究利用商業套裝計算流體動力學(Computational Fluid Dynamics, CFD)軟體STAR-CD搭配專業引擎網格生成軟體es-ice (Expert System for Internal Combustion Engines)
，針對一四行程單缸二閥機車引擎，計算引擎缸內氣流之滾轉運動與液滴霧化之交互作用的衍化，並加入缸內點火燃燒之計算，藉由此完整之缸內四行程之液滴霧化與燃燒計算後，探討氣流之滾轉運動與液滴霧化之衍化對之後缸內燃燒所造成之影響，並藉由循環渦度滾轉比及缸內平均壓力變化、溫度變化與壓力容積關係進一步了解引擎之性能，計算結果顯示出氣流之滾轉運動與液滴霧化之交互作用直接影響之後缸內之點火燃燒情形，因此往後在設計缸內直喷引擎時，可藉由先行計算缸內氣流之運動與液滴霧化之衍化，並以此結果做為一重要之參考指標後再加入燃燒之計算，並得知大概引擎之性能，藉此缸內氣流與燃燒模擬計算以減少初期設計缸內直噴引擎時所需之實驗之成本及時間。

The gasoline direct injection (GDI) has been engaged to internal combustion system of an automotive engine since 1995 by the Mitsubishi Motor. This technology has been widely used for car or motorcycle’s engine. It has been well recognized that the fuel consumption, exhaust emission, and engine performance can be drastically increased by application of the GDI technology. The GDI technology usually must be combined with the in cylinder flow tumble or swirl motion to regulate the charge mode the divide to homogeneous charge and stratify charge then engine stars the combustion process. The single cylinder, two valves four stokes, engine flows with fuel injection and combustion processes are calculated by a commercial software package of CFD code, the STAR-CD, combine with the es-ice (Expert System for Internal Combustion Engines) is a mesh generation tool. We know that the in-cylinder flow and atomization and sprays will affect combustion result and engine performance directly in this study. For engine CFD calculation, it should be calculate the in-cylinder flow motion and it’s affected for atomization and sprays first then add the combustion calculation. It can determine the engine P-V diagrams and performance then reduce time and money for the first stage to design the GDI engine.

[1]Mayer, H., “Air Pollution in Cities,” Atmospheric Environment, Vol. 33 October 1999, pp. 4029-4036.
[2]Zhao, F., Lai, M. C., Harrington, D. L., “Automotive Spark-Ignited Direct-Injector Gasoline Engines,” Progress in Energy and Combustion Science, Vol. 25, 1999, pp. 437-562.
[3]Heywood, J. B., Internal Combustion Engine Fundamentals, McGraw-Hill, New York, 1988.
[4]Heywood, J. B., “Fluid Motion within the Cylinder of Internal Combustion Engine-The 1986 Freeman Scholar Lecture.” Journal of Fluids Engineering, Transactions of the ASME, Vol. 109, No. 1, 1987, pp. 3-35.
[5]Coz, J. F. L., Henriot, S., and Pinchon P., “An Experimental and Computational Analysis of the Flow Field in a Four-Valve Spark Ignition Engine-Focus on Cycle-Resolved Turbulence,” Journal of Engine, SAE Transactions-Section 3, Part 1, Vol. 99, 1990, pp. 294-321, SAE 900056.
[6]Han, Z., Reitz, R. D., “Effects of Injection Timing on Air-Fuel Mixing in a Direct-Injection Spark-Ignition Engine,” Journal of Engine, SAE Transactions-Section 3, Vol. 106, 1997, pp. 848-860, SAE 970625.
[7]Matsumura, E., Tomita, T., Takeda, K., Furuno, S., and Senda, J., “Analysis of Visualized Fuel Flow inside the Slit Nozzle of Direct Injection SI Gasoline Engine,” Journal of Engine, SAE Transactions-Section 3, Vol. 112, 2003, pp. 238-245, SAE 2003-01-0060.
[8]Tanaka, Y., Takano, T., Sami, H., Sakai, K., and Osumi, N., “Analysis on Behaviors of Swirl Nozzle Spray and Slit Nozzle Spray in Relation to DI Gasoline Combustion,” Journal of Engine, SAE Transactions-Section 3, Vol. 112, 2003, pp. 218-235, SAE 2003-01-0059.
[9]Papageorgakis, G., Assanid, D. N., “Optimizing Gaseous Fuel-Air Mixing in Direct Injection Engines Using an RNG Based k-ε Model,” Journal of Engine, SAE Transactions-Section 3, Vol. 107, 1998, pp. 82-107, SAE 980135.
[10]Tomoda, T., Sasaki, S., Sawada, D., Saito, A., and Sami, H. “Development of Direct Injection Gasoline Engine-Study of Stratified Mixture Formation,” Journal of Engine, SAE Transactions-Section 3, Vol. 106, 1997, pp. 759-766, SAE 970539.
[11]Harada, J., Tomita, T., Mizuno, H., Mashiki, Z., and Ito, Y., “Development of Direct Injection Gasoline Engine,” Journal of Engine, SAE Transactions-Section 3, Vol. 106, 1997, pp. 767-776, SAE 970540.
[12]Ohsuga, M., Shiraishi, T. Nogi, T., Nakayama, Y., and Sukegawa, Y., “Mixture Preparation for Direct-Injection SI Engine,” Journal of Engine, SAE Transactions-Section 3, Vol. 106, 1997, pp. 794-801, SAE 970542.
[13]Rotondi, R., Bella G., ”Gasoline direct injection spray simulation,” International Journal of Thermal Sciences 45 (2006) 168-179
[14]Warsi, Z. U. A., “ Conservation Form of the Navier-Stokes Equations in General Nonesteady Coordinates,” AIAA Journal, Vol. 19, No 2, February 1981, pp. 240-242.
[15]Auriemma, M., Caputo, G., Corcione, F. E., and Valentino, G., “Fluid-Dynamic Analysis of the Intake System for a HDDI Diesel Engine by STAR-CD Code and LDA Technique,” Journal of Engines, SAE Transactions-Section 3, Vol. 112, 2003, pp. 21-28, SAE 2003-01-0002.
[16]Nonaka, Y., Horikawa, A., Nonaka, Y., Hirokawa, M., and Noda, T., “Gas Flow Simulation and Visualization in Cylinder of Motor-Cycle Engine,” Journal of Engines, SAE Transactions-Section 3, Vol. 113, 2004, pp. 1710-1714, SAE 2004-32-0004.
[17]Versteeg, H. K. and Malalasekera, W., An Introduction to Computational Fluid Dynamics-The Finite Volume Method, Addison Wesley Longman Limited, New York, 1995.
[18]楊賀順, 平頂與凹面活塞四閥四行程引擎的缸內流場滾轉運動與紊流衍化：PIV量測技術的開發與應用, 國立台灣科技大學機械工程技術研究所碩士論文, 2004。
[19]林岱衛, 不同進氣道設計的四行程單缸引擎缸內流場與紊流特性的 PIV診測, 國立台灣科技大學機械工程技術研究所碩士論文, 2004。