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You searched for subject:(Liquid Fuel Sprays). Showing records 1 – 2 of 2 total matches.

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Indian Institute of Science

1. Rakesh, P. A Study of the Characteristics of Gas-On-Liquid Impinging Injectors.

Degree: PhD, Faculty of Engineering, 2018, Indian Institute of Science

The work presented here pertains to investigations on gas-on-liquid type of impinging injectors with a generic approach with prospective applications in several areas, and at places with particular emphasis on cryogenic or semi-cryogenic liquid propellant rockets. In such rockets, one of the components arrives at the injector in a gaseous phase after passing through the regenerative coolant passages or a preceding combustion stage. Most often, the injectors in such systems are of shear coaxial type. The shear coaxial injectors suffer from several disadvantages like complexity in design, manufacture and quality control. Adoption of impinging jet configuration can alleviate these problems in addition to providing further benefits in terms of cost, robustness in high temperature environment and manifolding. However, there is very little literature on gas-on-liquid injectors either in this context or in any other Even for the simplest form of impinging injectors such as like-on-like doublets, literature provides no conclusive direction at describing a spray from the theoretical models of physical mechanisms. Empirical approach is still the prime mode of obtaining a proper understanding of the phenomena. Steady state spray characterization includes mainly of describing the spatial distribution of liquid mass and drop size distribution as a function of geometric and injection parameters. The parameters that are likely to have an impact on spray characteristics are orifice diameter, ratio of orifice length to diameter, pre-impingement length of individual jets, inter orifice distance, impingement angle, jet velocity and condition of the jet just before impingement. The gas-on- liquid configuration is likely to experience some qualitative changes because of the expansion of the gas jet. The degree to which each one of the above variables influences the drop size and mass distribution having implication to combustion performance forms the core theme of the thesis. A dedicated experimental facility has been built, calibrated and deployed exhaustively. While spray drop size measurement is done largely by a laser diffraction instrument, some of the cases warranted an image processing technique. Two different image processing algorithms are developed in-house for this purpose. The granulometric image processing method developed earlier in the group for cryogenic sprays is modified and its applicability to gas-on-liquid impinging sprays are verified. Another technique based on the Hough transform which is feature extraction technique for extracting quantitative information has also been developed and used for gas-on-liquid impinging injectors. A comparative study of conventional liquid-on-liquid doublet with gas-on-liquid impinging injectors are first made to establish the importance of studying gas-on-liquid impinging injectors. The study identifies the similarities and differences between the two types and highlights the features that make such injectors attractive as replacements to coaxial… Advisors/Committee Members: Raghunandan, B N (advisor).

Subjects/Keywords: Impinging Injectors; Impinging Atomizers; Gas-On-Liquid Impinging Injectors; Liquid Propellant Rockets; Impinging Jet Injectors; Atomizers; Cryogenic Rocket Injectors; Impinging Fuel Injector Atomization; Impinging Injectors Spraying; Image Processing - Spraying; Gas-On-Liquid Impinging Sprays; Liquid-on Liquid Impingement; Aerospace Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rakesh, P. (2018). A Study of the Characteristics of Gas-On-Liquid Impinging Injectors. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/3126

Chicago Manual of Style (16th Edition):

Rakesh, P. “A Study of the Characteristics of Gas-On-Liquid Impinging Injectors.” 2018. Doctoral Dissertation, Indian Institute of Science. Accessed March 05, 2021. http://etd.iisc.ac.in/handle/2005/3126.

MLA Handbook (7th Edition):

Rakesh, P. “A Study of the Characteristics of Gas-On-Liquid Impinging Injectors.” 2018. Web. 05 Mar 2021.

Vancouver:

Rakesh P. A Study of the Characteristics of Gas-On-Liquid Impinging Injectors. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2018. [cited 2021 Mar 05]. Available from: http://etd.iisc.ac.in/handle/2005/3126.

Council of Science Editors:

Rakesh P. A Study of the Characteristics of Gas-On-Liquid Impinging Injectors. [Doctoral Dissertation]. Indian Institute of Science; 2018. Available from: http://etd.iisc.ac.in/handle/2005/3126


Indian Institute of Science

2. Deshmukh, Devendra. Studies On Automization And Sprays Of Plant Oil Biofuels Using Laser-Based Diagnostics.

Degree: PhD, Faculty of Engineering, 2014, Indian Institute of Science

Atomization characteristics of liquid fuel sprays control combustion efficiency and emissions in engines. The present work is motivated by the need to study the atomization and spray structure of vegetable oil biofuels for which no data in the literature exists. In this work, various laser-based diagnostic techniques such as laser shadowgraphy, Particle/Droplet Image Analysis (PDIA) and Laser Sheet Dropsizing (LSD) are applied for studying atomization characteristics, tip penetration, droplet size and liquid volume fraction of Pongamia vegetable oil (SVO) and its blends with diesel. A constant volume high pressure spray visualization chamber is designed and fabricated to study SVO sprays at high gas pressure and temperature conditions. This optical chamber can be used for gas pressures up to 60 bar and temperatures up to 600 K. Optical access inside the chamber is provided through four quartz windows to perform various optical spray diagnostic studies. A high pressure spray injection facility based on components of common rail diesel injection system is designed. This facility can provide an injection pressure of up to 1700 bar with independent control over injection duration and timing. A marked difference is observed between diesel and SVO spray structures under atmospheric gas pressure condition. A very interesting observation related to the behavior of 100% SVO fuel when sprayed into atmospheric pressure is the presence of an intact liquid core even at injection pressure as high as 1600 bar. The presence of liquid core at high injection pressures is attributed to the high viscosity of SVOs and the non-Newtonian behavior of these oils under high pressure and shear. The spray characterization of the oil and its blends at high gas pressure shows that although the atomization is dramatically different from that at atmospheric gas pressure, it is still incomplete even at very high injection pressures. For a gas pressure of 30 bar, it is observed that the Sauter Mean Diameter (SMD) for Pongamia oil is more than twice that of diesel. A new method of simultaneously obtaining two-dimensional droplet size and quantitative liquid volume fraction data in sprays has been developed. Measurements with this method reveal a higher liquid volume fraction at the central axis of spray for Pongamia oil compared to that of diesel indicating potentially poor air-fuel mixing. The experimental data obtained and the spray tip penetration correlations developed for the vegetable oils and blends serve as useful inputs for fuel injection and engine system designers. Advisors/Committee Members: Ravikrishna, R V (advisor).

Subjects/Keywords: Liquid Fuel Sprays; Combustion Efficiency; Laser-based Diagnostics; Vegetable Oil Biofuels - Spray Atomization; Vegetable Oil Biofuels - Spray Structure; Plant Oil Biofuels; High Pressure Spray Visualization Chamber; Straight Vegetable Oil Sprays; Biofuels; Heat Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Deshmukh, D. (2014). Studies On Automization And Sprays Of Plant Oil Biofuels Using Laser-Based Diagnostics. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/2419

Chicago Manual of Style (16th Edition):

Deshmukh, Devendra. “Studies On Automization And Sprays Of Plant Oil Biofuels Using Laser-Based Diagnostics.” 2014. Doctoral Dissertation, Indian Institute of Science. Accessed March 05, 2021. http://etd.iisc.ac.in/handle/2005/2419.

MLA Handbook (7th Edition):

Deshmukh, Devendra. “Studies On Automization And Sprays Of Plant Oil Biofuels Using Laser-Based Diagnostics.” 2014. Web. 05 Mar 2021.

Vancouver:

Deshmukh D. Studies On Automization And Sprays Of Plant Oil Biofuels Using Laser-Based Diagnostics. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2014. [cited 2021 Mar 05]. Available from: http://etd.iisc.ac.in/handle/2005/2419.

Council of Science Editors:

Deshmukh D. Studies On Automization And Sprays Of Plant Oil Biofuels Using Laser-Based Diagnostics. [Doctoral Dissertation]. Indian Institute of Science; 2014. Available from: http://etd.iisc.ac.in/handle/2005/2419

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