scholarly journals Study on the Design Criteria of the Coaxial Injector for a LOX/Hydrogen Rocket Engine —Evaluation of Design for Injectors of the LE-5 Engine and Its Derivatives—

2007 ◽  
Vol 50 (169) ◽  
pp. 201-208 ◽  
Author(s):  
Nobuyuki YATSUYANAGI
Author(s):  
Youngbin Yoon ◽  
Gujeong Park ◽  
Sukil Oh ◽  
Jinhyun Bae

Studies on combustion instability in liquid rocket engines are important in improving combustion efficiency andpreventing combustion chamber losses. To prevent combustion instability, methods such as baffles and cavities are used. The injector is located in the middle of the perturbation-propagation process in the rocket engine, so it is important to study the suppression of combustion instability using the design of the injector. Much research has been focused on the study of liquid excitation in a single injector; however, the actual injector used in a liquid rocket engine is a coaxial injector. In this study, the dynamic characteristics of a gas-centred swirl coaxial injector were investigated by varying the gap thickness and momentum-flux ratio. Spray photographs were captured by synchronizing a stroboscope and digital camera, and a high-speed camera and Xenon lamp were also used. To measure the liquid film, a measurement system was implemented using the electrical conductance method. For excitation of the gas, an acoustic speaker was used to impart a frequency to the gas. The gGas velocity and effect of excitation were measured by hot-wire anemometry. A mechanical pulsator was used for liquid flow excitation. Liquid fluctuation was measured by a dynamic pressure sensor. In both gas and liquid excitation cases, the gain increased as the gap thickness decreased and the momentum-flux ratio increased. From these results, it can be concluded that gap thickness and momentum-flux ratio are major factors in suppressing combustioninstability. DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4653


2016 ◽  
Vol 9 (2) ◽  
pp. 127-140 ◽  
Author(s):  
Rahul Anand ◽  
PR Ajayalal ◽  
Vikash Kumar ◽  
A Salih ◽  
K Nandakumar

To achieve uniform and efficient combustion in a rocket engine, a fine uniform spray is needed. The same is achieved by designing an injector with good atomization characteristics. Gas-centered swirl coaxial (GCSC) injector elements have been preferred recently in liquid rocket engines because of an inherent capability to dampen the pressure oscillations in the thrust chamber. The gas-centered swirl coaxial injector chosen for this study is proposed to be used in a semi-cryogenic rocket engine operating with oxidizer rich hot exhaust gases from the pre-burner and liquid kerosene as fuel. In this paper, nine different configurations of gas-centered swirl coaxial injector, sorted out by studying the spray angle and coefficient of discharge with swirl number varying from 9 to 20 and recess ratio of 0.5, 1, and 1.5 are investigated for their atomization characteristics. Spray uniformity, spray cone angle, and droplet size in terms of Sauter mean diameter and mass median diameter are studied at various momentum flux ratios for all configurations. Sauter mean diameter is almost independent of recess ratio, whereas cone angle was inversely proportional to the recess ratio. A finer atomization was observed for injectors of high swirl number but the pressure drop also increased to achieve the same flow rate. An injector of medium swirl number and recess ratio of 1.5 is deemed most fit for above-mentioned application.


1995 ◽  
Vol 11 (3) ◽  
pp. 513-518 ◽  
Author(s):  
Wolfgang Mayer ◽  
Gerd Krulle

2018 ◽  
Vol 34 (2) ◽  
pp. 354-373 ◽  
Author(s):  
Tuan M. Nguyen ◽  
Pavel P. Popov ◽  
William A. Sirignano

2020 ◽  
Vol 1 (2) ◽  
pp. 34-56
Author(s):  
Elyna Amir Sharji ◽  
Lim Yan Peng ◽  
Peter Charles Woods ◽  
Vimala Perumal ◽  
Rose Linda Zainal Abidin

The challenge of transforming an empty space into a gallery setting takes on the concept of place making. A place can be seen as space that has meaning when the setting considers space, surroundings, contents, the people and its activities. This research concentrates on investigating how visitors perceive the space by gauging their sense of place (sense of belonging towards a place). Galleries are currently facing changes in this technological era whereby multiple content and context, space and form, display modes, tools and devices are introduced in one single space. An observational study was done during the Foundation Studies Annual Exhibition held at Faculty of Creative Multimedia, Multimedia University. The exhibition was curated and managed by staff and students of Foundation Year showcasing an array of design works. Analogue and digital presentations of paintings, drawings, sculptures, photography and video works were displayed.. The outcome of this research will contribute towards a better design criteria of place making which affects individual behaviour, social values and attitudes. Characterizing types of visitor experience will improve the understanding of a better design criteria of place making, acceptance, understanding and satisfaction.


2012 ◽  
Vol 132 (12) ◽  
pp. 1140-1145 ◽  
Author(s):  
Yuichi Takai ◽  
Yuhki Naganuma ◽  
Sho Takayanagi ◽  
Toru Sasaki ◽  
Takashi Kikuchi ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document