➨㸳ྕᵝᘧ               ㄽᩥᑂᰝࡢせ᪨༤ኈࡢᑓᨷศ㔝ࡢྡ⛠༤ ኈ 㸦  ᕤᏛ  㸧Ꮫ఩ᤵ୚ࡢせ௳Ꮫ఩つ๎➨㸲᮲➨㸯࣭㸰㡯ヱᙜẶྡ㥪 ὥுㄽ ᩥ 㢟 ┠Adhesion Characteristics of Fuel Spray Impinging on Flat Wall for Gasoline Engine㸦ᖹᯈቨ㠃࡟⾪✺ࡍࡿ࢞ࢯࣜࣥᄇ㟝ࡢᾮ⭷ᙧᡂ࡟㛵ࡍࡿ◊✲㸧ㄽᩥᑂᰝᢸᙜ⪅୺  ᰝ   ᩍ ᤵ    す⏣ ᜨဢ             ༳ᑂᰝጤဨ   ᩍ ᤵ    ᯇᮧ ᖾᙪ           ༳ᑂᰝጤဨ   ෸ᩍᤵ    ᑿᙧ 㝧୍             ༳ᑂᰝጤဨ   ෸ᩍᤵ    ஭ୖ ಟᖹ             ༳ࠝㄽᩥᑂᰝࡢせ᪨ࠞ

Spray-wall impingement is a widespread phenomenon applied in many fields,
inlcuding spray-wall cooling precess, spray coating process and fuel spray atomization ininternal combustion engines. Although the spray impingement has been investigated fordecades, the mechanisms of the interaction between spray and wall are still far from being
fully understood. In gasoline direct injection (GDI), it is difficult to avoid the fuel adhesionon the piston and sylinder surfaces. The wet wall caused by impingement affects theair-fuel mixture formation process, which is a possible source of unburned hydrocarbons(UHC) and particulate matters (PM), making it difficult for direct injection spark ignition(DISI) engines to meeting the future requirements of particle number (PN) regulations.
The novelty of this study lies in the correlation between the impinging spray and fueladheion formation together to better understand the spray-wall impingement in gasoline
engine. To present this work, the thesis is organized as follows:
Chapter 1 is entitled as “Introduction”. First of all, a review of previous works on thedevelopment of DISI engines, impinging spray and fuel adhesion formation as well as its
relative experimental methods were presented in this chapter.
Chapter 2 is entitled as “Experimental apparatus and measurement methods”. It
introduced the experimental apparatus implemented in this study, such as constanthigh-pressure chamber, impingement system and the observation techniques applied in thisinvestigation.
Chapter 3 is entitled as “Fuel adheison formation under non-evaporation conditions”.
The spray characteristics and fuel adhesion evolution were experimentally investigatedunder non-evaporation conditions in this chapter. The effect of pressure, roughness of thewall surface, impingement distances were tested in this chapter.
Chapter 4 is entitled as “Fuel adheison formation under evaporation conditions”. The
effects of ambient temperatures and hole diameters on the spray impingement and fueladhesion formation were studied. Furthermore, the different mechanisms in fuel adhesion
formation were discussed in this chapter.
Chapter 5 is entitled as “Microscopic behaviors of impinging spray”. To correlate thespray behaviors with the fuel adhesion, it illuminated the microscopic characteristics ofimpinging spray under different conditions, then, the droplets diameter and velocity werereported before and after impingement. Finally, the relationships between droplets and fueladhesion were summarized and compared with the single droplets behavior in this chapter.
Chapter 6 is entitled “Conclusions”. The main findings of this study and general
conclusions on the evolution of imping spray and fuel adheison formation for gasoline
engine were summarized, ans some recommendations of future work in this theme wereconducted as well in this chapter.
௨ୖ㸪ᑂᰝࡢ⤖ᯝ㸪ᮏㄽᩥࡢⴭ⪅ࡣ༤ኈ㸦ᕤᏛ㸧ࡢᏛ఩ࢆᤵ୚ࡉࢀࡿ༑ศ࡞㈨᱁ࡀ࠶ࡿ
ࡶࡢ࡜ㄆࡵࡽࢀࡿࠋഛ⪃㸸ᑂᰝࡢせ᪨ࡣ㸪1,500 Ꮠ௨ෆ࡜ࡍࡿࠋ