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Results for “Hypergolic Rocket Propellants”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records

Pulse performance analysis for small hypergolic-propellant rocket engines

Small rocket engine tests were conducted for the purpose of obtaining pulse performance data to aid in preliminary design and evaluation of attitude control systems. Both monopropellant and hypergolic bipropellant engines of thrust levels from 1 to 100 lbs were tested. The performance data for the hypergolic propellant rockets are compared with theoretical performance calculated from idealized chamber filling and evacuation characteristics. Electromechanical delays in valve response and heat transfer characteristics were found to cause substantial deviation between theoretical and test performance. The theoretical analysis is modified to obtain a semi-empirical model for hypergolic propellant rockets which is demonstrated to be reasonably accurate for two different engine configurations over a considerable range of duty cycles.

Smith, G. W.↗

Pulse performance analysis for small hypergolic propellant rocket engines

Small rocket engine tests were conducted for the purpose of obtaining pulse performance data to aid in preliminary design and evaluation of attitude control systems. Both monopropellant and hypergolic bipropellant engines of thrust levels from 5 to 445 N (1 to 100 lb) were tested. The performance data for the hypergolic propellant rockets are compared with theoretical performance calculated from idealized chamber filling and evacuation characteristics. Electromechanical delays in valve response and heat transfer characteristics were found to cause substantial deviation between theoretical performance and test performance. The theoretical analysis is modified to obtain a semiempirical model for hypergolic propellant rockets.

Smith, G. W.↗

Computational analysis of liquid hypergolic propellant rocket engines

The combustion process in liquid rocket engines depends on a number of complex phenomena such as atomization, vaporization, spray dynamics, mixing, and reaction mechanisms. A computational tool to study their mutual interactions is developed to help analyze these processes with a view of improving existing designs and optimizing future designs of the thrust chamber. The focus of the article is on the analysis of the Variable Thrust Engine for the Orbit Maneuvering Vehicle. This engine uses a hypergolic liquid bipropellant combination of monomethyl hydrazine as fuel and nitrogen tetroxide as oxidizer.

Krishnan, A.↗

Development of an advanced rocket propellant handler's suit

Most launch vehicles and satellites in the US inventory rely upon the use of hypergolic rocket propellants, many of which are toxic to humans. These fuels and oxidizers, such as hydrazine and nitrogen tetroxide have threshold limit values as low as 0.01 PPM. It is essential to provide space workers handling these agents whole body protection as they are universally hazardous not only to the respiratory system, but the skin as well. This paper describes a new method for powering a whole body protective garment to assure the safety of ground servicing crews. A new technology has been developed through the small business innovative research program at the Kennedy Space Center. Currently, liquid air is used in the environmental control unit (ECU) that powers the propellant handlers suit (PHE). However, liquid air exhibits problems with attitude dependence, oxygen enrichment, and difficulty with reliable quantity measurement. The new technology employs the storage of the supply air as a supercritical gas. This method of air storage overcomes all of three problems above while maintaining high density storage at relatively low vessel pressures (<7000 kPa or approximately 1000 psi). A one hour prototype ECU was developed and tested to prove the feasibility of this concept. This was upgraded by the design of a larger supercritical dewar capable of holding 7 Kg of air, a supply which provides a 2 hour duration to the PHE. A third version is being developed to test the feasibility of replacing existing air cooling methodology with a liquid cooled garment for relief of heat stress in this warm Florida environment. Testing of the first one hour prototype yielded data comparable to the liquid air powered predecessor, but enjoyed advantages of attitude independence and oxygen level stability. Thermal data revealed heat stress relief at least as good as liquid air supplied units. The application of supercritical air technology to this whole body protective ensemble marked an advancement in the state-of-the-art in personal protective equipment. Not only was long duration environmental control provided, but it was done without a high pressure vessel. The unit met human performance needs for attitude independence, oxygen stability and relief of heat stress. This supercritical air (and oxygen) technology is suggested for microgravity applications in life support such as the Extravehicular Mobility Unit. c 2001. Elsevier Science Ltd. All rights reserved.

Hazardous Substances↗

OMV/VTE variable thrust engine analysis

The objective of the present work is to develop a predictive CFD based analytical tool for the Variable Thrust Engine (VTE) in the Orbital Maneuvering Vehicle (OMV). This objective is being accomplished within the framework of the Los Alamos KIVA computer code for chemically reactive flows with sprays. For the OMV application, the main structure of KIVA is to be retained while reformulating many of the phenomenological submodels, enhancing some of the numerics, and adding more features. The analytical model consists of the general conservation equations for two-phase reactive flows and of submodels for turbulence, chemical reactions, and bipropellant sprays. Tailoring this model to the OMV engine brings about the added complexities of combustion and flow processes that occur in a liquid hypergolic propellant rocket chamber. This report exposes the foundation upon which the analytical tool is being constructed and developed. Results from a cursory computational exercise involving the simulation of the flow and combustion processes in a hypothetical N2H4/N204 rocket engine thrust chamber is presented and discussed.

Larosillere, L.↗

OMV/VTE variable thrust engine analysis

The objective of the present work is to develop a predictive CFD based analytical tool for the variable thrust engine (VTE) in the orbital maneuvering vehicle (OMV). This objective is being accomplished within the framework of the Los Alamos KIVA computer code for chemically reactive flows with sprays. For the OMV application, the main structure of KIVA is to be retained while reformulating many of the phenomenological submodels, enhancing some of the numerics, and adding more features. The analytical model consists of the general conservation equations for two phase reactive flows and of submodels for turbulence, chemical reactions, and bipropellant sprays. Tailoring this model to the OMV engine brings about the added complexities of combustion and flow processes that occur in a liquid hypergolic propellant rocket chamber. This report exposes the foundation upon which the analytical tool is being constructed and developed. Results from a cursory computational exercise involving the simulation of the flow and combustion processes in a hypothetical N2H4/N2O4 rocket engine thrust chamber is presented and discussed.

Larosillere, Louis↗

Design and Development of Functionally Operative and Visually Appealing Remote Firing Room Displays

This internship provided an opportunity for an intern to work with NASA's Ground Support Equipment (GSE) for the Spaceport Command and Control System (SCCS) at Kennedy Space Center as a remote display developer, under NASA mentor Kurt Leucht. The main focus was on creating remote displays for the hypergolic and high pressure helium subsystem team to help control the filling of the respective tanks. As a remote display developer for the GSE hypergolic and high pressure helium subsystem team the intern was responsible for creating and testing graphical remote displays to be used in the Launch Control Center (LCC) on the Firing Room's computer monitors. To become more familiar with the subsystem, the individual attended multiple project meetings and acquired their specific requirements regarding what needed to be included in the remote displays. After receiving the requirements, the next step was to create a display that had both visual appeal and logical order using the Display Editor, on the Virtual Machine (VM). In doing so, all Compact Unique Identifiers (CUI), which are associated with specific components within the subsystem, will need to be included in each respective display for the system to run properly. Then, once the display was created it needed to be tested to ensure that the display runs as intended by using the Test Driver, also found on the VM. This Test Driver is a specific application that checks to make sure all the CUIs in the display are running properly and returning the correct form of information. After creating and locally testing the display it will need to go through further testing and evaluation before deemed suitable for actual use. By the end of the semester long experience at NASA's Kennedy Space Center, the individual should have gained great knowledge and experience in various areas of display development and testing. They were able to demonstrate this new knowledge obtained by creating multiple successful remote displays that will one day be used by the hypergolic and high pressure helium subsystem team in one of the LCC's firing rooms to fill the new Orion spacecraft.

Ground Support Systems↗

Development and Testing of Functionally Operative and Visually Appealing Remote Firing Room Displays and Applications

This internship provided an opportunity for an intern to work with NASA's Ground Support Equipment (GSE) for the Spaceport Command and Control System (SCCS) at Kennedy Space Center as a remote display developer, under NASA technical mentor Kurt Leucht. The main focus was on creating remote displays and applications for the hypergolic and high pressure helium subsystem team to help control the filling of the respective tanks. As a remote display and application developer for the GSE hypergolic and high pressure helium subsystem team the intern was responsible for creating and testing graphical remote displays and applications to be used in the Launch Control Center (LCC) on the Firing Room's computers. To become more familiar with the subsystem, the individual attended multiple project meetings and acquired their specific requirements regarding what needed to be included in the software. After receiving the requirements for the displays, the next step was to create displays that had both visual appeal and logical order using the Display Editor, on the Virtual Machine (VM). In doing so, all Compact Unique Identifiers (CUI), which are associated with specific components within the subsystem, were need to be included in each respective display for the system to run properly. Then, once the display was created it was to be tested to ensure that the display runs as intended by using the Test Driver, also found on the VM. This Test Driver is a specific application that checks to make sure all the CUIs in the display are running properly and returning the correct form of information. After creating and locally testing the display it needed to go through further testing and evaluation before deemed suitable for actual use. For the remote applications the intern was responsible for creating a project that focused on channelizing each component included in each display. The core of the application code was created by setting up spreadsheets and having an auto test generator, generate the complete code structure. This application code was then loaded and ran on a testing environment set to ensure the code runs as anticipated. By the end of the semester-long experience at NASA's Kennedy Space Center, the individual should have gained great knowledge and experience in various areas of both display and application development and testing. They were able to demonstrate this new knowledge obtained by creating multiple successful remote displays that will one day be used by the hypergolic and high pressure helium subsystem team in the LCC's firing rooms to service the new Orion spacecraft. The completed display channelization application will be used to receive verification from NASA quality engineers.

Display Devices↗

Physical Simulation of Rocket Exhaust Aerodynamics Using Heated Ethane: Conceptual Foundations

Heated ethane (C2H6) has been proposed as an alternative to inert gases for use as a motive fluid in the experimental simulation of rocket exhaust plumes. By adjusting stagnation temperature, the isentropic exponent of ethane can be tuned to approximate those produced by common rocket propellants including hydrogen, hypergols, alcohols, and hydrocarbons. As a result, ethane can be made to follow a nozzle expansion process which is nearly identical to realistic rocket engine flow fields. Additionally, its high auto-ignition temperature and resistance to condensation enable the testing of expansion ratios much larger than conventional inertgas testing. NASA SSC has performed quasi-one-dimensional analyses using the Chemical Equilibrium with Applications (CEA) code as a preliminary means to compare flow fields produced by non-reacting ethane to those of reacting combustion products. A LO2/LH2 rocket engine operating at a chamber pressure of 5.0 MPa and a mixture ratio of 6.1 was used as an example case to demonstrate ethane’s efficacy as a simulant. Errors for key similarity parameters were compared to legacy cold-flow test methods. Additional errors induced by machining tolerances and chemical impurities were also examined. Results suggest that at a 3% geometric scale and ~500 K ethane stagnation temperature, an error of less than 2.5% throughout the flow field is realistically achievable along the dimensions of Mach number, Reynolds number, pressure ratio, and isentropic exponent. The development of an experimental test bed for validation of this configuration is currently underway.

Jones, Daniel R.↗

A Historical Analysis of Crane Mishaps at Kennedy Space Center

Cranes and hoists are widely used in many areas. Crane accidents and handling mishaps are responsible for injuries, costly equipment damage, and program delays. Most crane accidents are caused by preventable factors. Understanding these factors is critical when designing cranes and preparing lift plans. Analysis of previous accidents provides insight into current recommendations for crane safety. Cranes and hoists are used throughout Kennedy Space Center to lift everything from machine components to critical flight hardware. Unless they are trained crane operators, most NASA employees and contractors do not need to undergo specialized crane training and may not understand the safety issues surrounding the use of cranes and hoists. A single accident with a crane or hoist can injure or kill people, cause severe equipment damage, and delay or terminate a program. Handling mishaps can also have a significant impact on the program. Simple mistakes like bouncing or jarring a load, or moving the crane down when it should go up, can damage fragile flight hardware and cause major delays in processing. Hazardous commodities (high pressure gas, hypergolic propellants, and solid rocket motors) can cause life safety concerns for the workers performing the lifting operations. Most crane accidents are preventable with the correct training and understanding of potential hazards. Designing the crane with human factors taken into account can prevent many accidents. Engineers are also responsible for preparing lift plans where understanding the safety issues can prevent or mitigate potential accidents. Cranes are widely used across many areas of KSC. Failure of these cranes often leads to injury, high damage costs, and significant delays in program objectives. Following a basic set of principles and procedures during design, fabrication, testing, regular use, and maintenance can significantly minimize many of these failures. As the accident analysis shows, load drops are often caused or influenced by human factors. Therefore, proper training and understanding of crane safety throughout the workforce is critical. It is important that the engineers designing the cranes, lift planners preparing the lift plans, operators performing the lifts, and training officers conducting the operator training all understand the problems that can happen with cranes and how to ensure the safety of the workforce and equipment being lifted.

Materials Handling↗