記述言語：日本語   掲載種別：学位論文（博士）  

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DOI： 10.14988/0002000440

CiNii Research

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

本研究では吸気管内燃料噴射式火花点火機関の冷機始動を想定し，マルチサイクルの燃料噴射による液膜形成過程の把握を目的とした．本報では，風洞装置にて燃料噴射圧力と管内流動速度を変化させ，壁面に形成される液膜厚さを計測した．また，拡大撮影より取得した噴霧液滴群のウェーバー数分布より液膜形成過程を考察した．

DOI： 10.11351/jsaeronbun.55.113

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本機械学会  

<p>The atomization process of fuel spray injection in internal combustion engines affects the spray mixture formation process, the combustion characteristics, and the formation of toxic substances. Therefore, several optical measurement procedures have been developed and applied to capture spray features, including imaging methods and laser diagnostics. It has been concluded that the spatial resolution of fine spray droplets detection in imaging with silver halide film is much better than with a CCD imaging device. Therefore, the authors previously developed a novel imaging technique called Super High Spatial Resolution Photography (SHSRP), which allows for whole spray imaging while maintaining the spatial resolution of tiny droplets. This is a wide-field, high-resolution imaging method that can measure the entire spray area at the droplet scale. However, the image analysis method analyzes the intensity gradient of the outer edge of the droplet, and the accuracy of droplet analysis deteriorates as the droplet diameter is small. In this study, a new image analysis method with wide-field and high-resolution images acquired by SHSRP was developed to improve the analysis accuracy of spray droplets. The analysis method of depth of object field, which depends on droplet size, was changed from one-dimensional analysis of the intensity gradient of the outer edge of the droplet to two-dimensional analysis using the intensity deviation of the entire droplet area. For the developed analysis method, analysis of error based on scattering theory was conducted and the droplet capture ratio in diesel spray was analyzed to verify the accuracy. As a result, it was found that the particle size distribution obtained has no peaks due to noise effects, and that the presented analysis method is accurate enough to characterize the particle size distribution of diesel spray.</p>

DOI： 10.1299/transjsme.23-00141

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出版者・発行元：SAE Technical Papers  

Computational Fluid Dynamics (CFD) simulation is widely used in the development and validation of automotive engine performance. In engine simulation, spray breakup submodels are important because spray atomization has a significant influence on mixture formation and the combustion process. However, no breakup models have been developed for the fuel spray with plate-type multi-hole nozzle installed in port fuel injection spark ignition (SI) engines. Therefore, the purpose of this study is to simulate spray formation in port fuel injection precisely. The authors proposed the heterogeneous sheet breakup model for gasoline spray injected from plate type multi-hole nozzle. The novel breakup model was developed by clarifying the phenomenological mechanism of the spray atomization process. In this paper, this model was improved in dispersion characteristics and evaluated by the comparison of the model calculation results with experimental data. As the results, the heterogeneous sheet breakup model can describe accurately spray atomization feature of the spray injected from the plate type multi- hole nozzle in port fuel injection condition.

DOI： 10.4271/2023-32-0091

Scopus

出版者・発行元：SAE Technical Papers  

In this study, the authors analyze the concentration distribution of an evaporative spray mixture with LIEF (Laser induced exciplex fluorescence) method, which is a type of optical measurement. LIEF method is one of the optical measurements for obtaining the spray concentration distribution for separating vapor/liquid phases based on the fluorescence characteristics. In this paper, a quantitative concentration distribution analysis method for wall impingement spray in heterogeneous temperature field has been proposed. Then, a series of experiments were performed in varying injection pressure and ambient density. As a result, a two-dimensional concentration distribution was obtained for the free spray and wall impingement spray.

DOI： 10.4271/2023-32-0015

Scopus

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

本研究では噴霧‐壁面間干渉による液膜形成過程を考察するため，壁面衝突距離および壁面温度をパラメータとして壁面衝突噴霧による液膜の付着量，付着面積ならびに液膜温度の解析を行った．そし，実機関を想定し雰囲気から液膜に与えられる熱移動量，液膜の蒸発に必要な熱量を算出しPM排出過程に関する考察を行った．

DOI： 10.11351/jsaeronbun.54.711

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

本研究ではPM,PN排出低減のため噴霧‐壁面間干渉による液膜形成過程の詳細な把握を目的とした．本報では，定容容器を用いて壁面温度のみを変化させ，壁面に衝突する特性が同一の噴霧液滴群により形成される液膜の液膜温度と液膜厚さを計測することで液膜の温度変化が液膜形成過程に与える影響を解析した．

DOI： 10.11351/jsaeronbun.54.704

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本機械学会  

<p>Direct fuel injection spray is used to improve thermal efficiency and environmental performance in SI engines. A mixture is formed through momentum exchange between fuel droplets and ambient gas, along with mixing accompanied by droplets evaporation and diffusion. Both the droplets development derived from the liquid fuel atomization and the entrainment ambient air predominate the mixture formation process. The purpose of this study is to elucidate the momentum exchange characteristics of the spray formed by a single-hole injector for direct injection gasoline engines. To clarify the momentum exchange characteristics of spray droplets, the spray was visualized by optical experiments and the spray development process was analyzed. The parameters are injection pressure and ambient density. A comparison of experimental results and a model analysis of a single droplet movement was conducted, and different of deceleration characteristics were evaluated. In the case of the fuel spray, the induced ambient air by the spray tip droplets decreases the relative velocity between the spray droplets and the spray internal flow. A model for predicting the temporal variation of the spray tip penetration from the different of momentum exchange characteristics between the spray and the droplet was proposed.</p>

DOI： 10.1299/transjsme.23-00037

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

本研究の目的は，吸気管噴射用マルチホールノズルの噴霧微粒化過程の解明および分裂過程の数値解析による高精度な予測である．本報では，既報での現象論に基づく液膜分裂過程のモデル解析に加え液糸端が表面張力により収縮する影響を考慮した数値解析における噴霧分裂過程を表現するサブモデルを開発した．

DOI： 10.11351/jsaeronbun.54.8

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

本研究では，機関の始動および冷機状態の吸気管内における燃料噴霧の壁面付着特性の把握を目的としている．本報では，静止場および流動場における燃料噴霧特性を散乱光撮影により解析し，燃料噴霧の壁面付着特性をTIR-LIF法により解析した結果を報告する．

DOI： 10.11351/jsaeronbun.54.14

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

直噴ガソリンエンジンでは零度を下回る冷間始動時でのPM排出低減が重要性を増している．本研究では，低温環境下における壁面衝突噴霧により形成された燃料液膜に対して噴霧液滴の影響を受けずに計測できるTIR-LIF法を適用し燃料および壁面温度を同時冷却した際の衝突期間中を含めた液膜形成過程の結果を報告する．

DOI： 10.11351/jsaeronbun.53.1192

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

A breakup model used in spray combustion simulations was developed to predict the breakup process of spray droplets, which has large influences on the mixture formation and the combustion process in internal combustion engines. Taylor Analogy Breakup (TAB) Model is widely used as a droplet breakup model. Improved TAB (ITAB) Model has been developed by improving model constants and the breakup/non-breakup boundary condition of TAB Model. ITAB Model reproduces the dimensionless breakup time based on the observation results of the single droplet breakup behavior and CFD simulation results. In this study, calculation methods of droplet diameter and droplet velocity after breakup in ITAB Model are modified to avoid fitting model constants during spray analysis. Droplet diameter after breakup is determined by calculating Sauter Mean Diameter and using the droplet diameter distribution after breakup based on the observation results of the single droplet breakup behavior. The calculation constant for Sauter Mean Diameter is a function of Weber number to reproduce the breakup phenomenon of single droplets. Droplet velocity after breakup is calculated based on the energy conservation law of droplets used in Enhanced TAB Model. This model shows that Sauter Mean Diameter after breakup is almost same and perpendicular motion of droplets after breakup is more active than TAB Model. This model also considers the effects of the fuel physical properties on breakup characteristics. Model analysis shows that droplet diameter after breakup of the high boiling point component fuel is larger under same conditions and the effect of temperature change is larger than that of the low boiling point component fuel

DOI： 10.20485/jsaeijae.13.4_155

Scopus

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その他リンク： https://www.jstage.jst.go.jp/article/jsaeijae/13/4/13_20224546/_article/-char/ja

出版者・発行元：COMODIA 2022 - 10th International Conference on Modeling and Diagnostics for Advanced Engine Systems  

In spray combustion simulation, many breakup models have been developed and introduced into CFD simulation to predict the breakup process of spray droplets, which is very important for the mixture formation process. Theoretical models such as Taylor Analogy Breakup (TAB) Model are widely used as a droplet breakup model. To make TAB Model an experimental model, Improved TAB (ITAB) Model has been developed based on the observation results of the single droplet breakup process. In this study, Modified Improved TAB (MITAB) Model was developed as the new droplet breakup model. The model modifies calculation methods of droplet diameter and droplet velocity after breakup in ITAB Model based on observation results of the single droplet breakup process. WAVE-MITAB Model which combined with WAVE Model and MITAB Model was introduced into KIVA as the new spray breakup model, and CFD analysis was performed. In addition, the applicability of WAVE-MITAB Model to non-evaporating diesel spray was investigated by varying the calculation constant of WAVE Model and comparing with other spray breakup models.

Scopus

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

J-GLOBAL

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本機械学会  

<p>In a direct-injection gasoline engine, strict control of pollutant emissions at cold start is a critical point to comply with new regulations, and the fuel film formed by spray impingement on the piston wall is closely related. In this context, the purpose of this study is to clarify the fuel film formation process of spray impinging on a low temperature wall. Total internal reflection laser induced fluorescence (TIR-LIF) method was applied to the fuel film formed by wall impingement gasoline spray. TIR-LIF method can measure the fluorescence from fuel film without the influence of the spray droplet. The fluorescence intensity from the fuel film depends on the film thickness and temperature. In this paper, the temperature dependence of the fluorescence from the fuel film was investigated under the condition that the laser light is totally reflected from the top surface of the film. The order of magnitude of the heat transfers due to the mixing of spray droplets and fuel film, the heat transfer from the ambient gas, and the heat transfer from the wall were compared and modeled. A method to simultaneously calculate the unsteady change in fuel film thickness and fuel film temperature was developed. Then, the model analysis method was applied to the measured experimental data and verified.</p>

DOI： 10.1299/transjsme.21-00379

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J-GLOBAL

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

本研究では，多噴孔ノズルにおけるディーゼル噴霧の噴霧間干渉がエントレインメント機構に及ぼす影響の解明を目的としている．本報では，レーザ誘起蛍光法および粒子画像流速測定法を用いて周囲空気流動を計測し，独自に算出した隣接噴霧間における周囲空気の取り込み干渉領域により隣接噴霧間の周囲空気流動把握を試みた．

DOI： 10.11351/jsaeronbun.53.484

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 自動車技術会  

低温環境下における直噴ガソリンエンジンの噴霧挙動はPM/PN抑制の観点から重要である．本研究では低温環境下におけるの噴霧挙動の把握を目的とし，先行研究例が少ない-20℃までの極低温状態を想定し，自由噴霧と壁面衝突噴霧の特性を計測し解析を行った．その結果を報告する．

DOI： 10.11351/jsaeronbun.53.491

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担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本機械学会  

The fuel injection in diesel engines have a significant effect on the engine performance. But there is little knowledge on the characteristics of dispersion of liquid phase concentration. The purpose of this study is to clarify the dispersion process of the liquid phase of diesel spray through quantitative analysis of the liquid phase concentration distribution in non-evaporating diesel spray. In this paper, a quantitative analysis method of the liquid phase concentration of diesel spray under non-evaporative conditions is developed. The cross-sectional mass flow of the fuel was obtained using the momentum theory from the measured concentration distribution of the liquid phase with the laser induced fluorescence method. The relationship between the fluorescence intensity and the liquid phase concentration was estimated. In addition, a scheme was developed to account for the attenuation of the laser light and fluorescence, which results in a quantitative spatial distribution of the liquid phase concentration. Using this method, the dispersion process of the liquid phase in diesel spray was evaluated.

DOI： 10.1299/transjsme.21-00376

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

<p>混合燃料の気液平衡や物性値を推定する多成分燃料噴霧モデルは、多成分燃料噴霧の各成分の燃料濃度分布特性を表現することができる。本報では、 WAVE-MTABモデルを分裂モデルに適用し、高噴射圧力条件下での2成分混合燃料の噴霧特性を解析した。その結果、高噴射圧力噴射条件下における2成分混合燃料噴霧の噴霧先端到達距離および各成分の燃料濃度分布を、実験結果と比較して再現することができた。</p>

DOI： 10.1299/jsmekansai.2021.96.2203

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

<p>本報では，非定常蒸発ガソリン噴霧を対象にエキサイプレックス蛍光法を用いた気液相二相の領域における蒸気形成過程の実験的な解析を報告する．本研究では，混合気の平均温度を用いて気液相二相領域の蒸気濃度を算出する画像処理法を開発した．本手法は，気相と液相間の蛍光の混信を考慮したものであり，これを蒸発過程にあるガソリン噴霧に適用した．その結果，噴霧の内部と外縁では異なる蒸発過程をとることがわかった．</p>

DOI： 10.1299/jsmekansai.2021.96.31005

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記述言語：日本語   出版者・発行元：公益社団法人 自動車技術会  

二成分燃料の噴霧に対してレーザ誘起蛍光法を用いて噴霧特性を計測し，同条件下での数値解析を行なった．その結果，燃料噴射圧力および雰囲気密度の増加により蒸発特性の違いによる各成分の蒸気を層状に形成する効果が小さくなり，低沸点成分の早期蒸発による混合促進効果が大きくなることがわかった．

DOI： 10.11351/jsaeronbun.52.923

CiNii Research

記述言語：日本語   出版者・発行元：公益社団法人 自動車技術会  

混合燃料の気液平衡や物性値を推定する多成分燃料噴霧モデルは，多成分燃料噴霧の燃料濃度分布特性を表現できる．本論文では，WAVE-MTABモデルを分裂モデルに適用し，高圧噴射条件下における二成分燃料噴霧の噴霧特性を解析した．その結果，二成分燃料噴霧の先端挙動及び各燃料の濃度分布を再現することができた．

DOI： 10.11351/jsaeronbun.52.125

CiNii Research

記述言語：日本語   出版者・発行元：公益社団法人 自動車技術会  

本研究は吸気管噴射用マルチホールノズルの噴霧微粒化過程の解明およびモデリングを目的としている．本報では，液膜分裂を線形安定性解析よりモデル化，エネルギスペクトルを用いて粒度分布のモデリングを行なった．モデル結果を燃料噴霧の可視化より得られた実験結果と比較しモデルの評価を行なった．

DOI： 10.11351/jsaeronbun.52.1047

CiNii Research

記述言語：日本語   出版者・発行元：公益社団法人 自動車技術会  

吸気管噴射用マルチホールノズルの噴霧微粒化過程の解明を目的とし，粒子追跡法を適用することにより液滴の動的特性について調査した．その結果，燃料液滴の分散角は液滴径によって異なることがわかった．また，液滴の分散方向は噴射条件の影響を大きく受け，噴射後の気液相互作用の影響は少ないことがわかった．

DOI： 10.11351/jsaeronbun.52.677

CiNii Research

記述言語：日本語   出版者・発行元：公益社団法人 自動車技術会  

吸気管噴射燃料噴霧について，無次元数を用いた噴流形態の分類およびシャドウグラフ撮影による液膜分裂過程の可視化を行なった．吸気管噴射条件の燃料噴霧は液膜を形成し，液滴への分裂は軸方向に分布を持って発生することが明らかとなった．また，液滴からさらに微小な液滴への分裂は観測されなかった．

DOI： 10.11351/jsaeronbun.52.671

CiNii Research

記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

<p>This paper reports the quantitative method of vapor concentration in unsteady evaporating gasoline type spray with Laser Induced Exciplex Fluorescence（LIEF）. The LIEF is an exciplex fluorescence method developed by Melton to visualize the liquid and vapor phases separately. In this study, iso-octane（92 vol%）, benzene（4 vol%）, and triethylamine（4 vol%） were used as a fluorescent agent that emit excited complex fluorescence that can optically separate fluorescence from the liquid phase and the vapor phase respectively. We tested the dependence of the fluorescence characteristics on the vapor concentration, ambient pressure, and ambient temperature when quantifying the vapor concentration. The relationship between the vapor concentration and the fluorescence intensity ratio was similar to the theoretical relationship. Furthermore, the relationship between the fluorescence intensity ratio and each parameter could be considered as a function of only its parameter. Since the fluorescence intensity is proportional to the laser incident light intensity and the emitted laser light has a Gaussian intensity distribution, the intensity distribution of the laser sheet light could be predicted, and the captured image could be corrected. For quantitative measurement, we used the image analysis method of vapor concentration quantification measurement of direct injection diesel spray developed by Senda et al. The quantitative distribution of vapor concentration was measured by applying the method to the results of simultaneous measurement of Mie scattering, exciplex fluorescence, and monomer fluorescence.</p>

DOI： 10.1299/transjsme.20-00099

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記述言語：日本語   出版者・発行元：一般社団法人 日本機械学会  

<p>This paper reports the quantitative analysis of vapor concentration in the mixture-liquid two-phase region with Laser Induced Exciplex Fluorescence（LIEF）for the unsteady evaporating gasoline type spray. These methods were used to analyze the mixture-liquid two-phase characteristics in the process of mixture formation. The exciplex fluorescence method, developed by Melton, is a method to optically separate the fluorescence of the liquid and vapor phases, but quantitative analysis of vapor concentration in the mixture-liquid two-phase e region is difficult due to fluorescence cross talk. In this study, the quantitative analysis of vapor concentrations using the average temperature of mixing was used to quantify the vapor concentrations in the mixture-liquid two-phase region by image processing that considers the fluorescence cross talk between the liquid and vapor phases. As a result, the vapor concentration, the temperature of the mixture, and the concentration distribution of the liquid phase in the mixture-liquid two-phase region of the spray cross section were obtained. Based on these results, the correlation diagram between vapor concentration and fluorescence intensity of the liquid phase and the relative frequency distribution of vapor concentration were calculated. A comparison was made between the characteristic values of the fuel and the temperature under the experimental conditions. It was found that the spray consisted mainly of a region where the liquid phase was almost absent and dilute vapors were formed, and a region where the liquid phase was present and formed dense vapors. The same analysis was performed to evaluate the process of vaporization of the spray mixture at different times from the start of injection.</p>

DOI： 10.1299/transjsme.20-00294

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開催年月日： 2023年

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開催年月日： 2022年

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記述言語：日本語  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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記述言語：日本語   会議種別：口頭発表（一般）  

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非定常気液二相流場における噴霧微粒化および混合気形成過程のモデル構築と数値解析 23KJ2075

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