Download or read book Propellant Tank Pressurization Modeling for a Hybrid Rocket written by Margaret Mary Fernandez and published by . This book was released on 2009 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Hybrid rockets are currently being examined as a simpler and safer alternative to solid and liquid rocket propulsion. A basic hybrid rocket oxidizer delivery system utilizes the self-pressurizing nature of a liquid oxidizer at ambient temperatures in conjunction with a non-condensable to provide a high oxidizer tank pressure that drives liquid oxidizer flow to the combustion chamber. In this study, the oxidizer fluid is nitrous oxide since it produces high vapor pressures at ambient temperatures, and helium is the pressurant. The goal of this thesis is to model the pressure draining history of the oxidizer tank to within +/- 5% accuracy. Previous studies of the self-pressurization processes in a propellant tank have focused on long-term cryogenic storage applications where the primary concern is heat leaking into the tank, causing unwanted pressure increases that result in propellant loss through necessary venting. Results of these cryogenic studies have been used to justify the inclusion of heat and mass transfer resistances in propellant tank models in order to be sufficiently accurate. However, these cryogenic studies were performed under conditions of very low vapor pressure and temperatures, and it is not clear that the conclusions drawn from such studies are valid for self-pressurization under ambient temperature conditions. Thus, the validity of simpler thermodynamically-based models has not been considered for self-pressurizing, draining tanks under high pressure conditions. In this study, two models are developed, both assuming thermodynamic equilibrium states at every point in time throughout draining. The firs model assumes the P-V-T behavior of the nitrous oxide/helium mixture follows the ideal gas law; the second model assumes that the mixture adheres to the non-ideal Peng-Robinson equation-of-state. Both models are compared to experimental data from pure nitrous oxide draining tests, published in G. Zilliac & M. Karabeyoglu (Modeling of Propellant Tank Pressurization, AIAA 2005-3549, 41st AIAA/ASME/ASEE Joint Propulsion Conference). Sensitivity studies have been performed in order to determine the effect of experimental error on the time-dependent flow from the tank and to assess the behavior of the models near physical extremes, such as high or low initial nitrous oxide fill-levels. Theoretical draining histories for the Peregrine hybrid sounding rocket (a joint effort between NASA Ames Research Center and Stanford University, soon to be launched from NASA Wallops Flight Facility, have also been examined. A variety of comparisons with available experimental data, theoretical sensitivity studies, and theoretical launch data demonstrates that the non-ideal draining model provides favorable agreement. The additional complexity introduced by a non-ideal equation-of-state is necessary due to the high pressures encountered in the tank during draining. Sensitivity studies reveal that small deviations in the initial temperature, initial fill-level, or the discharge coeffient can produce nearly 5% errors in liquid drain time, demonstrating the need for accurately measured model inputs and suggesting sources of error in experimental design. It is found that despite the highly desirable characteristic of a rocket oxidizer delivery system. The study provides a proposal for a new set of experiments necessary to assess and refine the theoretical models to allow for design and scale-up of hybrid rocket oxidizer delivery systems."--Abstract.
Download or read book Self pressurizing Propellant Tank Dynamics written by Jonah E. Zimmerman and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid rockets frequently use nitrous oxide as a self-pressurizing oxidizer, where the high vapor pressure of the oxidizer is used to force the liquid out of the propellant tank and into the combustion chamber. To study this system, a series of small-scale pressure vessels with optical access have been developed that can be filled with nitrous oxide and then drained in a manner that replicates the conditions within a hybrid rocket. A high-speed camera has been used to visualize the nitrous oxide within the propellant tank and identify relevant phenomena. Experiments have identified two separate temporal regimes that are common to all blowdown tests: a transient and steady state, each described by distinct features. The transient regime is characterized by a rapid pressure drop and recovery, with homogeneous condensation of the ullage and heterogeneous nucleation and growth of bubbles. During steady state regime the liquid and vapor are both homogeneous two-phase mixtures and the pressure drops in a linear fashion as the liquid drains from the tank. Carbon dioxide was identified as a possible simulant fluid for nitrous oxide, and comparison tests showed that it behaves as an accurate analog. This low-cost and safe simulant fluid enabled a large number of tests that examined the effect of parameter variations, including flow rate, fill level, temperature, and scaling effects. Experimental data from this system have been used to develop a new model for self-pressurizing propellant tank dynamics. This was done by blending the 0-D lumped-node methods of previous researchers with a novel 1-D method that captures the dynamics of a changing bubble population. The direct quadrature method of moments was used to develop partial differential equations for parameters of this distribution. The proposed model was compared against experimental data and shown to have good agreement. The pressure drop and recovery seen in the transient regime, which is not captured by previous models, is visible in the model predictions. Convergence studies were performed in order to determine suitable parameters of the numerical integration schemes and the discretizations used. To complete the model, numerous submodels were incorporated by using relations from various sources in the literature. The effect of variations in these submodels was studied in order to justify the selection of adjustable constants.
Download or read book Progress in Astronautics and Aeronautics written by and published by . This book was released on 1963 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pressurization Systems for Liquid Rockets written by United States. National Aeronautics and Space Administration and published by . This book was released on 1976 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Injectors for Use with High Vapor Pressure Propellants with Applications to Hybrid Rockets written by Benjamin S. Waxman and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in nitrous oxide based hybrid rockets is at an all time high. Nitrous oxide (N2O) is a unique oxidizer because it exhibits a high vapor pressure at room temperature (≈ 730 psia or 5.03 MPa). Due to this high vapor pressure, liquid nitrous oxide can be expelled from a tank without the use of complicated pumps or pressurization systems required by most traditional liquid rocket systems. This results in weight savings and design simplicity. Additional benefits of nitrous oxide include storability, ease of handling, and relative safety compared to traditional liquid oxidizers. The design and modeling of injectors for use with high vapor pressure propellants such as nitrous oxide is made complicated due to the possibility of two-phase flow. The operating pressures within rocket propellant feed systems can often drop below the vapor pressure for these unique propellants, especially within the injector. Injectors operating under these conditions are likely to exhibit cavitation, resulting in significant vapor formation and limitation of mass flow rate. A variety of two-phase flow models which attempt to account for this phenomenon are presented and discussed, however none have proven reliable enough to replace traditional experimental injector flow studies. For this reason, a small scale experimental injector cold flow rig was designed, and a test campaign was carried out in an effort to characterize the mass flow rate performance of nitrous oxide rocket injectors over a broad range of operating conditions. Some representative results from this campaign are presented. The Peregrine Sounding Rocket is a hybrid rocket that runs on paraffin wax and nitrous oxide. Its development is a joint effort between NASA Ames Research Center, Stanford University, and Space Propulsion Group, Inc. For years, progress of the Peregrine program has been hampered by combustion instability problems. Based upon results from the aforementioned small scale injector experiments, a powerful, yet simple solution to the so-called feed system coupled combustion instability was discovered, the details of which are presented. This work also led to the invention of a new class of rocket propellant injectors designed specifically to decrease the likelihood of this type of combustion instability. An in-depth discussion of the proposed design and operation of this novel injection scheme is included, along with the presentation of some prototype cold flow testing results which served as a successful proof of concept.
Download or read book Rocket Propellant and Pressurization Systems written by Elliot Ring and published by . This book was released on 1964 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrous Oxide State Estimation in Hybrid Rocket Oxidizer Tanks written by Steven Borgdorff and published by . This book was released on 2017 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an increasing interest in the use of hybrid rockets to accomplish tasks that require precise control of the craft. Fuel is being consumed as the craft is propelled, causing the mass of the rocket to change. In some hybrid rocket architectures, it is not possible to directly measure the mass of the oxidizer while the rocket is in flight. Further, controlling the flow rate of oxidizer is a method employed to control the overall thrust developed by a hybrid rocket. It is therefore important to understand how the changing state of the oxidizer may influence the mass flow rate of the oxidizer. For precise flight trajectory control, accurate estimates of the various states, including the mass of the rocket and remaining propellant are required. Nitrous oxide is frequently selected as an oxidizer as it is relatively safe to store and handle, plus it is self pressurizing. Both of these advantages reduce complexity and cost and increase safety in a rocket program. In theory, the mass of the rocket could be estimated with a very precise model. In practice, such models have not provided a satisfactory level of accuracy when estimating the remaining mass of oxidizer. The goal of this thesis is to accurately estimate the current mass of the oxidizer in the tank over time. The approach to solving this problem uses an Extended Kalman Filter to merge a model of the system states with available measurements of system states. An existing model is selected, analyzed and discussed. It assumes the gas phase of nitrous oxide approximates an ideal gas, and that the gas and liquid phases are saturated in isothermal and isobaric equilibrium. Some alterations to this model are proposed as they are found to increase the accuracy. The changes include a first-order delay in the flow through the injector and the system components included in the modeled thermal mass are modified. The model, and the available measurements are then implemented in an Extended Kalman Filter (EKF). The primary intent of the filter is to dynamically estimate the mass and properties of the oxidizer remaining in the rocket during flight. The EKF relies on updated measurements of the pressure in the oxidizer tank and the combustion chamber. The EKF discussed in this work is designed with the intent the flow rate of oxidizer can be controlled, and a dedicated flow rate control factor is included. However, the hardware for control systems for the mass flow rate are not a focus of this work. The EKF performance is simulated and measured based on data collected from ground testing. An improvement over the use of simulation alone is demonstrated.
Download or read book Hybrid Rocket Propulsion Design Handbook written by Ashley Chandler Karp and published by Academic Press. This book was released on 2023-10-07 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid Rocket Propulsion Design Handbook provides system scaling laws, design methodologies, and a summary of available test data, giving engineers all the tools they need to develop realistic hybrid system designs.Important supporting theory from chemistry, thermodynamics, and rocket propulsion is addressed, helping readers from a variety of backgrounds to understand this interdisciplinary subject. This book also suggests guidelines for standardized reporting of test data, in response to difficulties researchers have in working with results from different research institutes. Covers general theory, recent advances and current fragmented experimental results of hybrid rocket engines Outlines testing standards for hybrid researchers Provides guidance on how to use a freely available online code from NASA
Download or read book Numerical Modeling of Pressurization of a Propellant Tank written by Alok Majumdar and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles of Design of Dynamically Similar Models for Large Propellant Tanks written by Paul E. Sandorff and published by . This book was released on 1960 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modern Engineering for Design of Liquid Propellant Rocket Engines written by Dieter K. Huzel and published by AIAA. This book was released on 1992 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space Propulsion Analysis and Design written by Ronald Humble and published by Learning Solutions. This book was released on 1995-09-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only comprehensive text available on space propulsion for students and professionals in astronautics.
Download or read book Analysis of Cryogenic Propellant Tank Pressurization based upon Experiments and Numerical Simulations written by Carina Ludwig and published by Cuvillier Verlag. This book was released on 2014-09-04 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focus of this study is the pressurization system of a cryogenic liquid propellant tank for the launcher application. Objective of the pressurization system is to provide the required pressure evolution in the propellant tank for a proper operation of the engine. The motivation of this study is an improved understanding of the complex fluid-dynamic and thermodynamic phenomena during the active-pressurization process of cryogenic propellants in order to optimize the on-board pressurant gas mass. Therefore ground experiments, numerical simulations and analytical considerations were performed for the investigation of the initial active-pressurization phase. For the performed experiments, liquid nitrogen was used as cryogenic model propellant, which was actively pressurized under normal gravity conditions up to different final tank pressures. As pressurant gases, gaseous nitrogen and gaseous helium were used with different inlet temperatures. For the numerical analyses the commercial CFD program Flow-3D, a three-dimensional Navier-Stokes equation solver, was used.
Download or read book Advances in Hybrid Rocket Technology and Related Analysis Methodologies written by Carmine Carmicino and published by MDPI. This book was released on 2020-12-07 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is an amazing collection of technical papers dealing with hybrid rockets. Once perceived as a niche technology, for about a decade, hybrid rockets have enjoyed renewed interest from both the propulsion technical community and industry. Hybrid motors can be used in practically all applications where a rocket is employed, but there are certain cases where they present a superior fit, such as sounding rockets, tactical missile systems, launch boosters and the emerging field of commercial space transportation. The novel space tourism business, indeed, will benefit from their safety and lower recurrent development costs. The subjects addressed in the book include the cutting edge technology employed to push forward this relatively new propulsion concept, spanning systems to improve fuel regression rate, control of the mixture ratio to optimize performance, computational fluid dynamics applied to the simulation of the internal ballistics, and some other novel system applications.
Download or read book Liquid Rockets and Propellants written by Loren E. Bollinger and published by . This book was released on 1960 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Modeling of the Pressurization Process in a NASP Vehicle Propellant Tank Experimental Simulation written by G. P. Sasmal and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of a Heated hybrid Generated Gas Pressurization System for Propellant Tanks written by Donald H. Lee and published by . This book was released on 1963 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:
