نتایج جستجو برای: propellant saving
تعداد نتایج: 36016 فیلتر نتایج به سال:
This paper addresses different methods for determining the amount of extra propellant (flight performance reserve or FPR) that is necessary to reach orbit with a high probability of success. One approach involves assuming that the various influential parameters are independent and that the result behaves as a Gaussian. Alternatively, probabilistic models may be used to determine the vehicle and...
Application of Model Based Prognostics to Pneumatic Valves in a Cryogenic Propellant Loading Testbed
Pneumatic-actuated valves are critical components in many applications, including cryogenic propellant loading for space operations. For these components, failures need to be predicted so that components can be repaired to ensure mission success, i.e., health monitoring and fault prognostics is required. In order to develop, test, mature, and deploy valve prognostics algorithms, we have develop...
cerns in rocket motor design because of the enormous cost of typical payloads and, in the case of the Space Shuttle and other manned vehicles, for the crew’s safety. In the spring of 1999, for example, a series of three consecutive launch failures collectively cost more than US$3.5 billion. The most notorious launch failure, of course, was the tragic loss of the Space Shuttle Challenger and its...
This paper presents an overview of research activities at the Center for Simulation of Advanced Rockets (CSAR) at the University of Illinois at Urbana-Champaign. CSAR is one of five university-based research centers funded by the U. S. Department of Energy as part of the Accelerated Strategic Computing Initiative (ASCI). The purpose of ASCI is to advance the state of the art in computational si...
This paper presents the results of a comparative investigation into effects ignition method on ballistic properties three types propellants: single-base propellant, double-base propellant and low vulnerability (LOVA) as determined via closed vessel tests (CVT). Conventional gunpowder plasma jet methods were used. The influence values characteristics obtained in CVT was analysed. It found that h...
In order to aging study of the compsite solid propellants, usually the changes in propellant properties during warehousing and storage are measured, and then the shelf life of them estimated. In this regard, by applying the common methods based on mechanical tests, chemical and thermal analysis, the propellant properties due to aging and time lapse are measured. In this paper, first we remark t...
Nowadays solid propellant motors (SRMs) are widely used because of simple structure and reliability. One of the requirements in SRMs is high tensile and bonding strength of liner for integrity of grain structure and neutralizes stresses applying to motor. In this research, effect of curing agent ratio (NCO/OH) in the range of (R=0.9-1.4) on tensile strength of liner and bonding strength of line...
Autocatalysis decomposition of single and double-base propellants is caused to production of nitrogen oxides radicals. Produced radicals, meantime reducing the inner energy of propellant, increased the decomposition process. To restriction of this process, some materials were added to propellant formulation as a stabilizer. Common stabilizers are toxic therefore, decreasing the toxicity and enh...
Abstract In this work, the effects of quality and quantity of three stabilizers as AkarditeII, 2-NDPA and CentraliteI on the heat of explosion and stability of double-based is investigated The results showed that, by increasing the amount of AkarditeII and 2-NDPA increased stability of propellant and decreased heat of explosion. By replace AkarditeII and 2NDPA with CentraliteI and AkarditeI...
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