著者

段 智久 大石 直己 千田 二郎 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.60, no.577, pp.3192-3197, 1994-09-25 (Released:2008-03-28)

参考文献数

4

被引用文献数

1 6

---

In the experiments presented, a single diesel spray of n-tridecane was injected for a certain duration through a hole-type nozzle into a quiescent atmosphere at room temperature at high pressure. The experimental variables were nozzle hole dimensions such as the hole diameter dn, the hole length ln and the hole offset between the nozzle axis and the hole axis, and the nozzle needle lift, in order to assess the turbulent flow field inside the nozzle, and the other was the back pressure, in order to examine the effect of the ambient gas properties, especially its kinematic viscosity. The macroscopic spray structures were observed by using instantaneous photography and a high-speed video camera system. Furthermore, the microscopic structure was observed by meant of scattering photography of fuel droplets taken by the laser light sheet of a pulsed ruby laser, and the quantitative 2-D image of fuel concentration in the cross section of the spray containing its central axis was obtained by the image processing. From the experiments, the variation in the spray cone angle with the needle lift is promoted by the turbulence in the sac volume, and spray angle is closely related to the ambient kinematic vincosity.

著者

千田 二郎 柴田 一郎 段 智久 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.63, no.613, pp.3173-3178, 1997-09-25 (Released:2008-03-28)

参考文献数

8

被引用文献数

1 2

---

This study investigates the atomization mechanism of fuel spray dissolved in noncondensable gas, such as N2, CO2. The fuel spray was injected at room temperature and in an atmospheric pressure field through a diesel-hole-type nozzle. In this paper, N2 gas was dissolved into diesel fuel, n-tridecane, under several pressurized conditions using a gas bubbling method in a constant volume vessel. This fuel, with high gas solubility, was injected under several injection pressures using an accumulated injection system designed by the authors. It was found that the dissolved gas separated into gas bubbles like gas cavitation phenomena under the atmospheric field. The change in spray patterns caused by the gas solubility is discussed using photographs of the patterns.

著者

大嶋 元啓 松村 恵理子 千田 二郎 石田 耕三

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.849, pp.16-00491-16-00491, 2017 (Released:2017-05-25)

参考文献数

12

---

In this study, the novel flame synthesis method using flash boiling spray is proposed in order to form the homogeneous characteristics nanoparticle. In this method, the precursors are injected and the injected precursors are evaporated by flash boiling. The evaporated precursors form vapor and the nanoparticles are formed at high temperature with flame. The factors for homogeneous characteristics of nanoparticles are precursor, flash boiling spray, flame characteristics and nozzle. These factors affect each other and affect to the nanoparticle characteristics as diameter distribution and crystal characteristics. It is necessary to optimize these factors to form homogeneous characteristics particles. In the previous study, TiO2 nanoparticles were formed and the relationship between the flame and injection characteristics, and the particle characteristics were investigated. From the result, the equivalence ratio affects to the nanoparticle crystal characteristics and injection condition affect to the particle diameter and mass fraction of anatase phase. In this paper, TiO2 nanoparticles were produced and the particle property influenced by ambient pressure and particle trapping position is investigated. As the result, the mass fraction of TiO2 anatase phase decreases by increasing ambient pressure. The rutile phase is formed at the short nanoparticle trapping position. The factors such as precursors, injection condition and fuel/oxygen flow ratio for producing the anatase phase particle in this method was discussed.

著者

酒井 雄大 井森 恵太郎 松本 直樹 松村 恵理子 千田 二郎

出版者

公益社団法人 自動車技術会

雑誌

自動車技術会論文集 (ISSN:02878321)

巻号頁・発行日

vol.49, no.6, pp.1103-1107, 2018 (Released:2018-11-26)

参考文献数

6

---

筒内直接噴射式ガソリンエンジンはポート噴射式と比較し高効率・低エミッションである一方,非常に緻密な混合気分布の制御が求められる.本研究においては,燃料を加熱する手法による混合気分布の制御を目的とする.本報においては,急速圧縮膨張機関を用いて加熱噴霧が燃焼特性に及ぼす影響を把握する.

著者

高岸 佐代 高橋 知宏 段 智久 千田 二郎 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.65, no.631, pp.1128-1133, 1999-03-25 (Released:2008-03-28)

参考文献数

9

被引用文献数

2 1

---

The characteristics of combustion process in internal combustion engines are affected by mixing process between the injected fuel and the ambient gas. Therefore, it is necessary to understand the flow field in diesel fuel sprays. In this study, a single spray was injected into a quiescent atmosphere with room temperature at high pressure through a single hole nozzle for simplification. To discuss the flow field in diesel sprays, structure of the spray was visualized by laser light sheet method. And, it was revealed that the vortex structure inside the spray affects the classification of droplet particles by taking microscopic photographs of the droplets with high resolution film. And applying PIV method into the spray photography, both the formation of meandering structure of the spray mainstream and the ambient gas entrainment process are clarified.

著者

段 智久 高岸 佐代 大石 直己 千田 二郎 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.62, no.597, pp.2079-2085, 1996-05-25 (Released:2008-03-28)

参考文献数

15

被引用文献数

7 8

---

In the experiments presented here, a single diesel spray of n-tridecane was injected for a certain duration through a hole-type nozzle (ln/dn=1.1mm / 0.2mm) into a quiescent high pressure atmosphere at room temperature. We used the same amounts of fuel injection for each injection pressure and the same ambient gas density field for all injection experiments including tests of the effect of changing the ambient gas. The macroscopic spray structures were observed by instantaneous photography and using a high-speed video camera system. Furthermore, the microscopic structure was observed by means of laser light-scattering photography, fuel droplet distribution was measured using the laser light-sheet of a pulsed Nd-YAG laser, and the mean diameter of the drop was obtained through image processing by the laser extinction method. This study revealed that the diesel spray consisted of a number of large vortices, which was considered to be the coherent structure. With high ambient gas viscosity, the fuel droplet became smaller. It was also found that a large vortex existed at the tip of the spray.

著者

段 智久 高岸 佐代 大石 直己 千田 二郎 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.62, no.599, pp.2867-2873, 1996-07-25 (Released:2008-03-28)

参考文献数

14

被引用文献数

2 5

---

This study deals with the effect of the viscosity of the ambient gas on the atomization process of a diesel spray. The liquid fuel is injected through a single-hole nozzle (ln/dn=0.75 mm/0.25 mm)with the injection differential pressure of 16.2 MPa inside a constant-volume vessel under a high-pressure field at room temperature. In practical combustion chambers of diesel engines, the viscosity of the ambient gas varies mainly with its temperature. In this experiment, various gases (CO2, N2, Ar, Ne, and Ar+Ne) were utilized for the ambient atmosphere in order to change the ambient gas viscosity. The vaporization of fuel drops was negligible. This study, revealed that the higher the viscosity, the more the spray spreads in the radial direction, thus the spray angle increased and tip penetration decreased. The droplets became smaller and were distributed in the inner region of the cold-state diesel spray under high ambient viscosity conditions. Further more, it was found that processes of ligament formation in the liquid jet and initial atomization were affected by kinematic viscosity ratio between the liquid fuel and ambient gas, and the spray dispersion and mixing process in the downstream region was affected only by the ambient gas kinematic viscosity.

著者

草野 茂之 段 智久 千田 二郎 藤本 元

出版者

一般社団法人日本機械学会

雑誌

日本機械学会論文集. B編 (ISSN:03875016)

巻号頁・発行日

vol.65, no.630, pp.804-811, 1999-02-25

参考文献数

10

被引用文献数

2

---

In this study, new models on the new droplet evaporation taking account of the droplet surface temperature related to the modified Spalding model, on the ambient temperature and the mass fraction at the infinite-point was proposed and incorporated into KIVA-II code. These models were compared and reviewed with the droplet evaporation model of KIVA-II original code in relation to the standard Spalding model. As a results, it is found that the calculated results of droplet evaporation by new model agree well with actual phenomena.

著者

草野 茂之 段 智久 千田 二郎 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.65, no.630, pp.804-811, 1999-02-25 (Released:2008-03-28)

参考文献数

10

被引用文献数

3 4

---

In this study, new models on the new droplet evaporation taking account of the droplet surface temperature related to the modified Spalding model, on the ambient temperature and the mass fraction at the infinite-point was proposed and incorporated into KIVA-II code. These models were compared and reviewed with the droplet evaporation model of KIVA-II original code in relation to the standard Spalding model. As a results, it is found that the calculated results of droplet evaporation by new model agree well with actual phenomena.

著者

段 智久 高岸 佐代 千田 二郎 藤元 元

出版者

同志社大学

雑誌

同志社大学理工学研究報告 (ISSN:00368172)

巻号頁・発行日

vol.36, no.4, pp.225-251, 1996-03

著者

千田 二郎 柴田 一郎 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.63, no.613, pp.3179-3186, 1997-09-25 (Released:2008-03-28)

参考文献数

20

---

In this paper, propose a new fuel injection system using diesel fuel dissolved in liquefied CO2. The system has the capability of reducing both NOx and soot simultaneously. This concept strives to improve the atomization of fuel spray by flash boiling liquefied CO2 gas. Moreover, it is possible to control the combustion system, for instance, and internal EGR effect is produced by the separated CO2 gas. In this paper, the characteristics of diesel spray of the fuel dissolved with liquefied CO2 were investigated using several optical measurements and the variance of CO2 molar fraction, ambient pressure and ambient density under room-temperature conditions. The spray characteristics were revealed using analysis in chemical thermodynamics. The atomization and dispersion of a free spray composed of fuel dissolved in liquefied CO2 are much better than those of normal diesel fuel oil, due to the flash boiling process in the relatively low pressure field.

著者

川野 大輔 千田 二郎 和田 好充 藤本 元 石井 素 鈴木 央一 後藤 雄一 小高 松男

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.70, no.696, pp.2213-2219, 2004-08-25 (Released:2011-03-03)

参考文献数

20

被引用文献数

1

---

Original KIVA code cannot take account for the spray and combustion processes of multicomponent fuels. Therefore, it is necessary to produce the sub-models for multicomponent fuel using KIVA code. In this study, the modeling of detailed physical properties and evaporation process for multicomponent fuel was conducted. In addition, the effects of fuel composition in multicomponent fuel on vapor distribution, spray tip penetration, vapor mass and evaporation rate, and sauter mean diameter were numerically investigated by using KIVA 3 V code with this multicomponent fuel spray model. From the numerical results, the spray characteristics of multicomponent fuel varied with a change in mixing fraction in multicomponent fuel. Especially, the evaporation of multicomponent fuel was not necessarily improved, even if much amount of high volatility fuel was mixed in the multicomponent fuel.

著者

千田 二郎 錦織 環 北條 義之 塚本 時弘 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.60, no.578, pp.3556-3562, 1994-10-25 (Released:2008-03-28)

参考文献数

23

被引用文献数

2 4

---

This paper presents the model analysis of atomization and vaporization process in a flash boiling spray based on the experimental results. Two kinds of liquid fuel, n-Pentane and n-Hexane, are injected into quiescent gaseous atmosphere at room temperature with low pressure through a pintle-type injector. Then, in flash boiling spray region where the back pressure is below the saturated vapor pressure of fuel, the bubble nucleation process due to flash boiling is modeled by the nucleation rate equation. Furthermore, fuel vaporization process is assessed by considering bubble growth calculations of vapor cavitation phenomena and fuel evaporation due to heat transfer process. Accordingly, we could estimate quantitatively the transient changes in bubble diameter and vapor mass fraction inside the spray for each back pressure condition.

著者

千田 二郎 浅井 崇胤 川口 文悟 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.65, no.632, pp.1459-1466, 1999-04-25 (Released:2008-03-28)

参考文献数

15

---

The new injection system by using mixed fuel dissolved with liquefied CO2 was proposed in this paper. Liquefied CO2 was mixed into n-tridecane under pressurized state in order to promote the spray atomization and evaporation due to the effect of the flash boiling phenomena in fuel injection, and to control the combustion process due to the effect of internal EGR effect of CO2 gas. Therefore, the simultaneous reduction of soot and NOx cas be achieved effectively by use of this injection system. In this paper, the characteristics of diesel fuel spray dissolved with liquefied CO2 were investigated quantitatively by means of several optical measurements. And the spray characteristics were revealed by the analysis of chemical thermodynamics. As a result, the atomization of this fuel is promoted due to the flash boiling much more than n-tridecane as the reference of the normal fuel and the spray structure is highly diHerent from that of the normal fuel.Moreover, thenumerical analysis for the atomization and the vaporization process wan carried out based on the flash boiling spray models.

著者

千田 二郎 檜垣 智大 高橋 秀和 高木 靖雄 足立 正之 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.65, no.640, pp.4106-4112, 1999-12-25 (Released:2008-03-28)

参考文献数

12

被引用文献数

2 1

---

In previous multi-dimensional modeling on spray dynamics and vapor formation, single component fuel with pure substrance has been analyzed to assess the mixture formation process. Then it shold be expected that the evaporation process could be performed for the multi-component fuel such as actual Gasoline and Diesel gas oil. In this study, vapor liquid equilibrium prediction was conducted for multi component fuels such as 3 and 10 components mixed solution with ideal solution analysis and non ideal solution analysis. And the computation of distillation characteristics was conducted for the steady state fuel conditions to understand the evaporation process. As a result, calculated distillation characteristics is consistent well with experiment results. Further the vapor concentration was measured for the analysis of the binary fuel spray using IR absorption measurement method.

著者

巽 健 前田 篤志 宮田 哲次 小橋 好充 桑原 一成 松村 恵理子 千田 二郎

出版者

公益社団法人 自動車技術会

雑誌

自動車技術会論文集 (ISSN:02878321)

巻号頁・発行日

vol.47, no.6, pp.1291-1296, 2016 (Released:2018-01-29)

参考文献数

7

被引用文献数

9

---

ディーゼル機関は高い熱効率を有しているが,投入熱量の20~30%が冷却損失として失われており,熱効率を向上させる上で壁面熱伝達メカニズムの解明は重要である.そこで壁面挿入型定容燃焼容器を用いて火炎直接撮影および熱流束測定を行なうことでディーゼル火炎と壁面熱損失の相関性を調査した.

著者

吉田 裕平 西上 諒太 川端 裕二 表 洪志 松村 恵理子 千田 二郎

出版者

公益社団法人 自動車技術会

雑誌

自動車技術会論文集 (ISSN:02878321)

巻号頁・発行日

vol.47, no.3, pp.691-696, 2016 (Released:2018-01-29)

参考文献数

10

---

ディーゼル機関の更なる高効率化かつ低エミッション化が求められている.本研究ではEGRガスを燃料に溶解させ,気体の析出効果によって噴霧の微粒化を改善する手法の確立を目的とする.また,噴霧内のEGRガスが直接燃焼に寄与することでNOxの大幅な低減効果が期待できる.本報ではCO2の溶解が噴霧特性に与える影響を把握した.

著者

千田 二郎 錦織 環 北條 義之 塚本 時弘 藤本 元

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.60, no.578, pp.3551-3555, 1994-10-25 (Released:2008-03-28)

参考文献数

13

被引用文献数

3

---

In this study, the influence of the flash boiling phenomenon on the fuel spray characteristics was in vestigated using both experiments and model analysis. Pure liquid fuel of n-Pentane or n-Hexane is injected into a vessel under quiescent gaseous atmosphere at room temperature through a pintle-type injector. Fuel sprays are observed by taking photographs for variation of ambient back pressure. In particular, changes in spray characteristics with back pressure are examined in detail. The results show that the saturated vapor pressure of fuel is the most significant factor and the spray characteristics can be varied with the pressure difference between the back pressure and saturated vapor pressure. Furthermore, flow field of the fuel inside the nozzle is estimated with regard to bubble initiation inside the film flow.

著者

千田 二郎 山田 耕司 藤本 元 三木 英雄

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 B編 (ISSN:03875016)

巻号頁・発行日

vol.53, no.485, pp.176-182, 1987-01-25 (Released:2008-03-28)

参考文献数

19

被引用文献数

1 2

---

The purpose of this paper is to obtain fundamental information concerning the heat transfer process and breakup behavior characteristics of individual small droplets impinging upon a hot surface. A uniform sized water droplet array at room temperature under atmospheric pressure was produced by the vibratory method to impinge upon a heated flat copper surface. And then, heat transfer from a surface to the droplets is assessed by a transient technique. Further, the deformation and the breakup behavior owing to the impingement of the droplet is observed by means of a drum camera recording high-speed microscopic photographs. Heat transfer effectiveness in a low temperature range of less than 125°C decreases as droplet impingement frequency increases because of interference between the impinging droplet and the remaining liquid film on a surface. It is possible that heat transfer per droplet is transfermed into a heat transfer coefficient by use of droplet residence time and film contact area on a surface. And Variations in the heat transfor coefficient for a droplet array with surface temperature are measured by difference calculus of the one dimensional unsteady heat conduction equation.

著者

井上 泰宏 松浦 貴 千田 二郎

出版者

公益社団法人 日本マリンエンジニアリング学会

雑誌

マリンエンジニアリング (ISSN:13461427)

巻号頁・発行日

vol.46, no.2, pp.263-268, 2011 (Released:2013-10-23)

参考文献数

8

被引用文献数

1

---

Biodiesel fuel (BDF) is a renewable resource, and is a promising carbon neutral fuel. However, BDF has the properties of high viscosity and poor volatility. Therefore, the atomization of its spray seems to be inhibited, which results in problems such as severe engine deposits and injector coking. In this study, BDF is mixed with a low boiling fuel to improve its fuel properties. Ethanol was chosen as the fuel to be mixed with BDF because of its higher oxygen content, lower ignitability and higher volatility. The ethanol addition would exert a large influence on mixture formation, ignition, combustion, and exhaust emissions. In the experiments, the spray characteristics were measured by shadowgraph photography and Mie-scattered light photography, while the mixture concentration and ignitability were measured by chemiluminescence photography. The experimental results show that the liquid phase penetration decreased with increasing of the mixture ratio of ethanol to BDF, and the ignition timing and ignition position can be controlled by changing the mixture ratio of BDF and ethanol.