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Introduction to Rocketry
Published in Ahmed F. El-Sayed, Aircraft Propulsion and Gas Turbine Engines, 2017
In parallel staging schemes (Figure 18.20), solid or liquid rocket boosters are used to assist with liftoff. These are sometimes referred to as “stage 0.” In the typical case, the first stage and booster engines fire to propel the entire rocket upward. When the boosters run out of fuel, they are detached from the rest of the rocket and fall away. The first stage then burns to completion and falls off. For example, the Atlas is parallel staged; it has two booster engines that are fired along with the central sustainer engine at launch.
Numerical eigenfrequency and experimental verification of variable cutout (square/rectangular) borne layered glass/epoxy flat/curved panel structure
Published in Mechanics Based Design of Structures and Machines, 2022
Hukum Chand Dewangan, Nitin Sharma, Chetan Kumar Hirwani, Subrata Kumar Panda
The modern engineering structure and their components (air-plane fuselage, rocket booster, and ground vehicle) are replacing fast by the advanced fiber-reinforced composite due to their tailor-made properties. These structures are generally associated with cutouts because of their real-time applications like assemblies, windows, doors, passages for overhauling, etc. The cutouts are of different shapes (rectangular, circular and elliptical) and sizes associated with the structural components as per the specific applications. The impact of cutout on structural integrity is quite extensive when the structure operates under dynamic loading. The unwanted vibrations may cause uneven collapse because of the resonance, and the degree may extend in the presence of cutout. Therefore, to understand the consequence of cutout on the free vibration frequencies of the laminated structure is not only essential for the modeling but also challenging. The extensive studies related to the modal analysis of layered structure with cutout reported using the analytical and the numerical techniques, including various theoretical modeling discussed in the following lines.
Heat transfer measurements in a hydrogen-oxyfuel combustor
Published in Experimental Heat Transfer, 2021
Tom Tanneberger, Panagiotis Stathopoulos
A few attempts have been made to investigate the internal combustion of H and O experimentally. A German consortium repurposed a rocket combustor into a MW H/O steam generator to be used as a steam cycle booster [13–17]. In this particular case, the combustor walls had to withstand a heat load of to MW/m. They were convectively cooled with water, which was injected and evaporated downstream of the combustion chamber to control the combustor outlet temperature. Insufficient combustion efficiency and wall cooling effects [17] led to the termination of this project. Similar projects have also been carried out in Russia [18–20] and Japan [21–23] with similar technical challenges.
Considerations for Implementing Presidential Memorandum-20 Guidelines for Nuclear Safety Launch Authorization for Future Civil Space Missions
Published in Nuclear Technology, 2021
An example of a nonobvious reason is an accident scenario where the LV destructs on or near the launch pad. If the destruct charges on the LV’s strap-on solid rocket boosters ignite, large solid propellant fragments from their upper domes could be propelled vertically upward and then fall back on top of the spacecraft and/or MMRTG, with potential impact and crushing effects. Sandia National Laboratories (SNL), in developing the nuclear risk assessment (NRA) for the Mars 2020 mission’s EIS (Ref. 14), postulated that the impulse generated by a near-concurrent detonation of the central common core booster (CCB) could deflect these propellant fragments radially outward during their fallback, thereby lowering the probability of impacting the spacecraft and MMRTG (Ref. 16). In their memorandum, SNL noted there was “considerable uncertainty” in their calculations. Among these are the facts that (1) the detonation signals travel along the destruct lines at detonation velocities (4 to 10 km/s), not light speed (300 000 km/s), (2) the liquid propellant and liquid oxygen need time to mix to develop full impulse, and (3) the location of the CCB’s so-called center of explosion changes and is dependent on the degree of mixing of the propellant and oxidizer. SNL used their lower calculated probabilities in the NRA, with the intent of requesting more rigorous assessment of this accident scenario and probabilities for the FSAR.