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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 35 for “"rocket motors"”.
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MODIFICATION OF COMMERCIAL ROCKET MOTORS FOR TACTICAL APPLICATIONS
… modifications to commercial off-the-shelf solid rocket motors have been evaluated in support of the Naval Postgraduate School tactical rapid-response payload delivery vehicle. The modifications include a novel head-end ignition system and a tailorable nozzle end cap designed to provide reliable …
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Validation and implementation of optical diagnostics for particle sizing in rocket motors
Aluminum oxide(Al2O3) particles of known size distribution were cast into a solid propellant which burned at temperatures less than the melting point of Al2O3. Thus, particles of known size distribution existed at the nozzle inlet and in the plume. Malvern particle sizing instruments were used to …
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Development of low-thrust solid rocket motors for small, fast aircraft propulsion
… technologies do not meet. Solid propellant rocket motors could be used, but must be re-engineered to operate at much lower thrust and for much longer burn times than conventional small solid rocket motors. This imposes unique demands on the motor and propellant. This work investigates …
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Numerical Simulation and Inverse Design of Solid Rocket Motors with Non Uniform Ballistic Properties
L'abstract è presente nell'allegato / the abstract is in the attachment
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Stress analysis of rocket motors with viscoelastic propellant by a mixed finite element model
… semi-positive definite to positive definite. A rocket motor is composed of (1) case (2) propellant and (3) hollow air core and is modelled as an axisymmetric solid. The propellant of a rocket motor is treated as a viscoelastic material. Static and dynamic analyses are performed under (1) two …
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Dynamic Behaviour of Composite Structures Containing Viscoelastic Materials, with Applications to Solid Fuel Rocket Motors
… of forced harmonic vibration on solid fuel rocket motors. A rocket motor consists of the motor case (which contains the propellant) and the blast tube attached to the aft end. The propellant is a viscoelastic material, no reliable data on the complex modulii of the propellants were available …
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Development, modeling and testing of thermal protection systems in small, slow-burning solid rocket motors
… regime requires the use of a slow-burning solid rocket motor. To achieve long burn times, an end-burning grain configuration is required in addition to a burn rate suppressant. Such a propulsion system presents unique thermal challenges due to the long exposure times and the close proximity of …
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Investigation of the Stability of Metallic/Composited-Cased Solid Propellant Rocket Motors under External Pressure
Solid rocket motors consist of a thin metallic or composite shell filled with a soft rubbery propellant. Such motors are vulnerable and prone to buckling due to sudden external pressures produced by nearby detonation. The stability conditions of rocket motors subjected toaxisymmetric, external …
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The development and implementation of a hybrid rocket motor thrust stand to investigate the relationship between combustion chamber pressure and graphite rocket nozzle erosion in hybrid rocket motors
Rocket motors frequently implement carbon-based nozzle inserts to insulate the motor from the heat produced by combustion. Over time these inserts will erode due to oxidation at the surface wherein oxidizing species found in the combustion products react with the carbon to form carbon monoxide. It …
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Determination of the complex modulus of a solid propellant and random vibration analysis of the layered viscoelastic cylinders with finite element method
… random vibration testing of sampled solid rocket motors on electromagnetic or hydraulic shakers are routinely performed as an important experiment-oriented quality control strategy. Nevertheless, it is crucial to understand the dynamic structural behavior of these layered viscoelastic …
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An efficient technique for structural reliability with applications
… the design variables. An explicit solution for rocket motors consisting of propellant and steel case under environmental temperature variations is compared to the RSM technique. The method is then used for the analysis of rocket motors subjected to mechanical loads for which the stress analysis …
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Stress and reliability analysis of multilayered composite cylinder under thermal and mechanical loads
… displacement distributions and reliability of rocket motors under static or dynamic line loads are analyzed by an elasticity approach. Rocket motors are modeled as long hollow multilayered cylinders with an air core, a thick isotropic propellant inner layer and a thin orthotropic kevlar-epoxy …
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Preliminary design of a liquid bipropellant microfabricated rocket engine
… thesis discusses the design of a microfabricated rocket engine. Micro-rockets feature a thrust to weight ratio up to two orders of magnitude greater than conventional rocket motors at small thrust levels and hence are very attractive for satellite propulsion applications and micro-satellite …
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Comparison of Cation-Anion Oxidizer Pairings in Electrically Controllable Solid Propellants
… the lack of throttle-ability in solid propellant rocket motors. Existing studies have focused on propellants compositions using hydroxyl-ammonium nitrate, ammonium nitrate, or lithium perchlorate as oxidizers. Additionally, the thermochemical and electrochemical reaction mechanisms have not yet …
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An experimental investigation of the effects of acceleration on the combustion characteristics of an aluminized composite solid propellant
… characteristics of many solid propellant rocket motors have been drastically affected by the acceleration loads imposed during flight. The two modes of acceleration are spin-induced accelerations due to spin stabilization and longitudinal accelerations due to motor thrusting. The subject …
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Characterization of Shear Strengths and Microstructures for Solid Rocket Motor Insulation Materials
As advances in solid rocket technology push rocket motors to more extreme operating speeds and temperatures, it becomes increasingly important to have well-designed material systems capable of surviving these harsh conditions. One common component in these systems is the use of a fiber- and …
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Systems analysis of a microfabricated storable bipropellant rocket engine
… analysis of a storable bipropellant micro-rocket engine. Micro-rockets are built using MEMS technology and are projected to deliver a thrust to weight ratio up to two orders of magnitude greater than conventional rocket motors at small thrust levels making them very attractive for satellite …
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Towards Electrical Control Over Rocket Propellant Combustion
… of various propulsion systems. In solid rocket motors, active burn rate modulation has the potential to enable throttling. In spacecraft propulsion systems, electrolysis of propellants may provide a means to reduce energy requirements and eliminate the need for expensive catalysts. The …
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Manufacturing methods for a solid rocket motor propelling a small, fast flight vehicle
… around a long-endurance, end-burning solid rocket motor that provides 2-3 minutes of powered flight. Challenges exist for manufacturing solid rocket motors for small, fast aircraft such as Firefly. Achieving desired motor performance requires a void-free propellant grain and thermal liner …
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