A Helium Face Seal Application In a Liquid Oxygen Pump

1969 ◽  
Vol 91 (4) ◽  
pp. 668-674
Author(s):  
Walter J. Cieslik

The object of the work discussed in this paper was to develop a reliable helium gas shaft seal for use in an electric motor-driven, liquid oxygen pump on a space vehicle. The development effort covered tests on two basically different face seal designs, one with an attached carbon face and the other with a floating lap-fitted carbon face. Several bellows vibration damping devices and various seal material combinations were investigated.

2021 ◽  
pp. 107754632110036
Author(s):  
Shihui Huo ◽  
Hong Huang ◽  
Daoqiong Huang ◽  
Zhanyi Liu ◽  
Hui Chen

Turbo pump is one of the elements with the most complex flow of liquid rocket engine, and as an important component of turbo pump, an impeller is the weak point affecting its reliability. In this study, a noncontact modal characteristic identification technique was proposed for the liquid oxygen pump impeller. Modal characteristics of the impeller under three different submerged media, air, pure water, and brine with same density as liquid oxygen, were tested based on the noncontact modal identification technology. Submersion state directly affects the modal frequencies and damping ratio. The transient vibration response characteristics of the impeller excited by the unsteady flow field was achieved combining with unsteady flow field analysis and transient dynamic analysis in the whole flow passage of the liquid oxygen pump. Vibration responses at different positions of the impeller show 10X and 20X frequencies, and the amplitude at the root of short blade is significant, which needs to be paid more attention in structural design and fatigue evaluation.


1995 ◽  
Author(s):  
M Oike ◽  
R Nagao ◽  
M Nosaka ◽  
K Kamijo ◽  
T Jinnouchi
Keyword(s):  

2020 ◽  
Vol 57 (1) ◽  
pp. 133-140
Author(s):  
Dumitru Bolcu ◽  
Marius Marinel Stanescu ◽  
Ion Ciuca ◽  
Cosmin Mihai Miritoiu ◽  
Alin Dinita ◽  
...  

This paper studies the influence of the volume proportion between components on the mechanical behaviour of a hybrid resin obtained by combining the natural resin Dammar and epoxy resin. We analyse three sets of hybrid resin samples, in which we used a Dammar volume proportion of 60%, 70%, and 80% respectively and epoxy resin (employed together with its associated reinforcement in order to generate a quick process of polymerization). Following the tensile test we found the characteristic curves, the tensile strength and the elongation at break for each of the three types of resins. We also looked into the vibration damping properties of bars made of this resin. We experimentally determined the frequency and the damping coefficient of the first particular vibration mode for one bar taken out of each set of resins, with one end fixed and the other free. On the basis of the results, we calculated the loss coefficient for each type of resin.


1964 ◽  
Vol 86 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Wen-Jei Yang ◽  
J. A. Clark

By use of the source theory approximate solutions are obtained for determining (a) the growth of a vapor bubble in pure liquids and binary liquid mixtures and (b) the growth and collapse of a noncondensing, nonsoluble-gas bubble in a pure liquid. These approximate results for case (a) exhibit good agreement with the existing exact solutions. Case (b) may be applied to the injection of helium gas into liquid oxygen, a problem of current importance in cryogenic rocket systems.


1960 ◽  
Vol 92 (1) ◽  
pp. 48-51 ◽  
Author(s):  
C. F. Nicholls

A trap for flying insects that incorporates some of the principles described by Williams and Milne (1935) and Chamberlin and Lawson (1910) was constructed. It consists basically of two conical nets that rotate in a horizontal plane around a central axis that is driven by an electric motor through a series of pulleys. The efficiency of the trap is not affected by wind as an increased airflow through one net is balanced by a decreased airflow through the other. It is green in colour to blend with its surroundings. The trap (Fig. 1) is 5½ feet high at the centre. It has three main sections (Fig. 2): the framework, the drivillg mechanism, and the nets.


2011 ◽  
Vol 130-134 ◽  
pp. 438-441
Author(s):  
Yong Wang ◽  
Ying Zhang ◽  
Ji Fen Li

Based on the positional characteristic of ellipticorbit of four-bar linkage, we develop a device to support rehabilitation of a patient’s lower limb’s motion in two-dimensional plane. In addition, we use ADAMS software to analyze two aspects parameters. One aspect is about the horizontal and vertical displacement of four-bar mechanism of ellipticorbit. The other simulation is about angles θ1 (angle between thigh and the horizontal) and θ2 (angle between thigh and calf). Before using the device, we install them in both sides of a normal chair. Driven by electric motor, lower limbs can follow the trajectory to do rehabilitation exercise. Long-term exercise can help a patient to repair damaged muscles.


2021 ◽  
Vol 1 (10) ◽  
Author(s):  
Adisu Fanta Bate

AbstractThe effectiveness of entrepreneurial activities is not only determined by the quality of entrepreneurs but also by the ecosystem of entrepreneurship. The entrepreneurial ecosystem (EE) that nurtures low-quality “moppets” to highly impactful “gazelles” is being widely debated and on-demand in literature. This study, therefore, is aimed to advance the discussion and make a comparative analysis of the entrepreneurial ecosystem, which has been given a little attention, of BRICS club countries with an especial focus on South Africa, Brazil, and India. Various entrepreneurship-economic growth-related measures including Global Entrepreneurship Index (GEI), Global Competitiveness Index (GCI), Index Economic Freedom (IEF), and Legatum Prosperity Index (LPI) are used to compare the countries’ entrepreneurial ecosystem. Especially, the data set (2012–2018) of GEI was utilized for the analysis. According to GEI and GCI of 2018, China is leading BRICS club in terms of growth and entrepreneurial ecosystem. On the other side, LPI, IEF, and GEI put South Africa’s entrepreneurial ecosystem in a favorable position as compared to Brazil and India. South Africa performs poorly in startup skills, while both the latter ones are better and stand at the same level. This shows that South Africa’s tertiary education, coupled with low skill perception, is less effective in equipping the population to be entrepreneurs as compared to India and Brazil. Whereas Brazil and India are at their worst in internationalizing the country’s entrepreneurs and technological absorption, respectively. South Africa is more like India in product innovation and risk acceptance. On the other side, it is more like Brazil in risk capital, technological absorption, opportunity perception, and in their sluggish economic growth. Overall, South Africa (57th/140 as of 2018) is categorized among those poorly performing countries in terms of start-up skills, networking, technology absorption, human Capital, and risk capital pillars. The government of South Africa needs to primarily work on these bottle-neck pillars to improve its EE. To increase GEI by 5%, it should invest 77% of its extra resource on start-up skills, 18% on risk capital, and 5% on technology absorption. Applying GEI set up, this paper claims to have uniquely contributed to how to make a country comparison on the EE. Further empirical research can be done including all BRICS countries to bolster their development effort and on how to promote EE by tackling the underlying bottlenecks.


2016 ◽  
Vol 835 ◽  
pp. 805-809 ◽  
Author(s):  
René Drtina ◽  
Jaroslav Lokvenc ◽  
Josef Šedivý ◽  
Jan Škoda

The article deals concept of measuring the electric motor-generator sets and represents the completion of a comprehensive design laboratory for electrical energy mikrozdroje laboratories. Given that the test set is powered energy industrial installations can not underestimate the risks arising from its operations. The seemingly simple design of the electrical part with manual control may seem a step back (in particular, from the viewpoint of universal, sometimes precipitous and unnecessary digitization anything), on the other hand the solution chosen allows combination possibilities that are not in the conventional digital control feasible.


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