第５号様式
論文審査の要旨
博士の専攻分野の名称

博士 （工学）

学位授与の要件

学位規則第４条第１・２項該当

氏名

RIZAL MAHMUD

論 文 題 目
Experimental Study on Heat Transfer of Flat-Wall-Impinging Diesel Spray Flame（平板に衝突するディーゼル噴霧火炎の壁面熱伝達に関する実験的研究）
論文審査担当者
主査

教 授

西田 恵哉

印

審査委員

教 授

遠藤 琢磨印

審査委員

教 授

松村 幸彦

印

審査委員

准教授

尾形 陽一

印

〔論文審査の要旨〕
Despite increasing efficiency and improved fuel economy, heat loss still remains asa major factor, which contributes to substantial amount of energy loss in small size
direct injection diesel engines. Therefore, heat loss reduction, which affects engine
efficiency, has been of a challenging task. This heat loss occurs in various ways such as
cooling loss, exhaust loss, and friction loss. Of the cooling loss, heat loss through thecombustion chamber wall is the most significant one. Thus, a full understanding of theheat loss mechanism from combustion gas to cylinder wall would be needed tomaximize thermal efficiency in the design of future engines.
The aim of this study was to better understand the mechanism of heat transferfrom the spray flame to the impinging wall under the small Diesel engine–likecondition. To present this work, the dissertation is organized as follows:
Chapter 1 is entitled as “Introduction”. A review of previous work such as heattransfer in engine combustion chamber, heat transfer correlation, heat transfer of wall
impinging spray/flame and optical diagnostic technique for diesel spray were presented
in this chapter.
Chapter 2 is entitled as “Experimental apparatus, measuring methods, andexperimental conditions”. it described the experimental apparatus such as constantvolume vessel, fuel injection system, and impingement wall test rig, including theTFTHF sensors. The observation by high-speed video camera, two-color method, heat
flux measurement, and data acquisition are also introduced.
Chapter 3 is entitled as “Heat transfer under baseline condition”. It described thespray/flame behaviors and transient local heat flux characteristics under baseline
conditions.

Chapter 4 is entitled as “Heat transfer under various impinging distances”. The
effect of impingement distance on the heat flux on diesel spray flame was investigatedunder non-combustion and combustion conditions. The distribution of temperaturenear a wall and soot emission, respectively, by applying two-color techniques were also
discussed in this chapter.
Chapter 5 is entitled as “Effect of injection pressure and nozzle hole diameter”.
The spray flame behaviors of impinging spray and heat transfer characteristics under
different injection pressures and nozzle hole diameters were studied. Furthermore,heat transfer coefficient under non-combustion and combustion conditions werediscussed in this chapter.
Chapter 6 is entitled as “Effect of oxygen concentration on heat transfer”. The
transient heat flux under different oxygen concentrations were discussed in detail inthis chapter.
Chapter 7 is entitled as “Combined effect of impingement distance/injection
pressure and oxygen concentration/injection pressure”. The combination effect on heattransfer and showed the optimum result to decreasing heat transfer on a diesel engine
and a heat transfer correlation was expressed in this study.
Chapter 8 is entitled as “Conclusions”. General conclusions on spray flame
behavior and transient local heat flux in diesel-like conditions and recommendations
for future study were summarized in this chapter.
As mentioned above, As a result of the examination, this paper is judged to be ofhigh value from academic and engineering viewpoints, so the author of this paper isconsidered to be sufficiently qualified to receive a doctoral (engineering) degree.

備考：審査の要旨は，1,500 字以内とする。