Ditching Tests with a 1/16-size Model of the Navy XP2V-1 Airplane at the Langley Tank No. 2 Monorail
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This study examines the use of boron nitride (BN) and coke dust as alternative reductants for low-activity waste vitrification in scaled melter systems, intended to enhance operational flexibility at the Hanford Waste Treatment and Immobilization Plant. The baseline reductant, sucrose, while widely considered advantageous for glass production rates, produces challenging off gas emissions during processing. Early crucible-scale testing indicated that BN and coke effectively control foaming and glass redox, while significantly reducing acetonitrile emissions. Both real tank waste and simulant waste melter feeds were tested with BN and coke in this study. Rheological properties for melter feeds with both reductants were within operational limits, although the particle size of coke should be controlled and sufficient agitation is necessary to ensure smooth operations. While promising for handling and reduction of emissions, both simulant melter feeds demonstrated lower average glass production rates in the simulant melter system compared with sucrose. In the radioactive system, the rates were more comparable to previously measured low activity waste feeds on the order of 1285 kg m 2 day −1 for BN and 1671 kg m −2 day −1 for coke. Further scale-up testing is required to interpret the processing rates in the context of the full scale melter systems and evaluate the cost-benefit impact of these reductants on efficiency and sustainability.
This report details the results of a series of fluid motion experiments to investigate the use of magnets to orient fluids in a low-gravity environment. The fluid of interest for this project was liquid oxygen (LO2) since it exhibits a paramagnetic behavior (is attracted to magnetic fields). However, due to safety and handling concerns, a water-based ferromagnetic mixture (produced by Ferrofluidics Corporation) was selected to simplify procedures. Three ferromagnetic fluid mixture strengths and a nonmagnetic water baseline were tested using three different initial fluid positions with respect to the magnet. Experiment accelerometer data were used with a modified computational fluid dynamics code termed CFX-4 (by AEA Technologies) to predict fluid motion. These predictions compared favorably with experiment video data, verifying the code's ability to predict fluid motion with and without magnetic influences. Additional predictions were generated for LO2 with the same test conditions and geometries used in the testing. Test hardware consisted of a cylindrical Plexiglas tank (6-in. bore with 10-in. length), a 6,000-G rare Earth magnet (10-in. ring), three-axis accelerometer package, and a video recorder system. All tests were conducted aboard the NASA Reduced-Gravity Workshop, a KC-135A aircraft.
Three major projects were undertaken during the Summer 2013 USRP Internship: (A) assisting the cTAPS group with component and pressure vessel system analyses and documentation, (B) designing a hoisting fixture for a solid rocket motor, (C) finding an alternative to removing the DOT rated gaseous nitrogen tank from the roof for hydrostatic testing. Hypergolic Material Assessments (HMAs) and pressure calculations were performed on components of pressure systems. Additionally, component information was logged in the Standard Parts Database to provide a location where system designers can find information regarding components, including their specifications and compatibility with fluids. A hoisting fixture was designed to hoist a solid rocket motor and meets the specifications related to stress and size. However, there are issues with the fixtures bolt head allotment, the bolt spacing, and the complexity of the part. Finally, calculations were performed on an expiring DOT rated gaseous nitrogen tank in an attempt to re-rate it per ASME standards. This was unsuccessful so other options are being explored for the tank. While much progress was made on all three projects, there is still work to be performed on each project to achieve the desired results.
Madidrop is a rectangular ceramic tablet originally designed to dose a 10-20-liter volume of water with silver to act as a biocide for remote communities with unreliable water sources. Silver as a biocide is a proposed method to control bacteria on the International Space Station or future Artemis missions. This would replace iodine currently used due to issues with a dual biocide system in place between Russian and US segments and the extra cost of iodine removal required before consumption. NASA has been reviewing this Madidrop technology and its potential application with a water reclamation system on orbit to dose silver after purifying the water. While there are a couple alternative methods to dosing silver on station, this method is like the existing passive dosing method used currently to dose iodine. Tests conducted characterize the manufacturer’s original intent to leave the tablet in a tank for a specified amount of time before removing and testing alternative passive flow-through methods. Passive flow testing involved two options: keeping the tablet intact or crushing the tablet into smaller particle sizes to increase the surface area while varying particle sizes. The results of these tests revealed a large amount of silver output at first that quickly reduced to a constant lower output within a reasonable dosing concentration range. The initial high concentration peaks after a couple days of quiescence and could be useful for shocking the initial tank water contents. Madidrop used as a passive particle doser could act as a stand-in replacement for iodine in future spaceflight water reclamation systems.
Madidrop is a rectangular ceramic tablet originally designed to dose a 10-20-liter volume of water with silver to act as a biocide for remote communities with unreliable water sources. Silver as a biocide is a proposed method to control bacteria on the International Space Station or future Artemis missions. This would replace iodine currently used due to issues with a dual biocide system in place between Russian and US segments and the extra cost of iodine removal required before consumption. NASA has been reviewing this Madidrop technology and its potential application with a water reclamation system on orbit to dose silver after purifying the water. While there are a couple alternative methods to dosing silver on station, this method is like the existing passive dosing method used currently to dose iodine. Tests conducted characterize the manufacturer’s original intent to leave the tablet in a tank for a specified amount of time before removing and testing alternative passive flow-through methods. Passive flow testing involved two options: keeping the tablet intact or crushing the tablet into smaller particle sizes to increase the surface area while varying particle sizes. The results of these tests revealed a large amount of silver output at first that quickly reduced to a constant lower output within a reasonable dosing concentration range. The initial high concentration peaks after a couple days of quiescence and could be useful for shocking the initial tank water contents. Madidrop used as a passive particle doser could act as a stand-in replacement for iodine in future spaceflight water reclamation systems.
Calculating an accurate nutation time constant (NTC), or nutation rate of growth, for a spinning upper stage is important for ensuring mission success. Spacecraft nutation, or wobble, is caused by energy dissipation anywhere in the system. Propellant slosh in the spacecraft fuel tanks is the primary source for this dissipation and, if it is in a state of resonance, the NTC can become short enough to violate mission constraints. The Spinning Slosh Test Rig (SSTR) is a forced-motion spin table where fluid dynamic effects in full-scale fuel tanks can be tested in order to obtain key parameters used to calculate the NTC. We accomplish this by independently varying nutation frequency versus the spin rate and measuring force and torque responses on the tank. This method was used to predict parameters for the Genesis, Contour, and Stereo missions, whose tanks were mounted outboard from the spin axis. These parameters are incorporated into a mathematical model that uses mechanical analogs, such as pendulums and rotors, to simulate the force and torque resonances associated with fluid slosh.
Experimental aerodynamic investigations were conducted in the NASA Ames Research Center 3.5-Foot Hypersonic Wind Tunnel on a 0.010-scale model of the space shuttle vehicle orbiter and external tank (model no. 32 0T). The purpose of the test was to evaluate the basic hypersonic stability characteristics of the external tank and orbiter and to define orbiter plume effects on aero characteristics using solid plumes. The test was conducted at angles of attack from minus 10 deg to 30 deg and angles of sideslip of minus 10 deg thru 10 deg. Six component force data and static base pressures were recorded during the test.
Analytical models are presented for describing the heat and mass transfer and the energy distribution in the contents of a cryogenic propellant tank, under varying gravity levels. These models are used to analytically evaluate the effectiveness of a wall heat exchanger as a means of controlling the pressure in the tank during flight and during fill operations. Pressure and temperature histories are presented for tanks varying in size from 4 to 22.5 feet in diameter and gravity levels from 0-1. Results from the subscale test program, utilizing both non-cryogenic and cryogenic fluid, designed to evaluate a tank wall heat exchanger are described and compared with the analytical models. Both the model and test results indicate that a passive tank wall heat exchanger can effectively control tank pressure. However, the weight of such a system is considerably higher than that of an active mixer system.
Marine energy structures are typically made of advanced composite materials and are subjected to extreme ocean environments in service. In extreme ocean environments, seawater currents and waves load structures repeatedly, which cause two environmental conditions: water intrusion and mechanical fatigue. In prior research, the two environmental conditions were applied sequentially, where composite specimens were aged and then mechanically tested. To understand the combined effects of dynamic loading and water intrusion on composite materials, the present study involves the static and fatigue four-point bend testing of composite coupons in a water tank. The water tank was designed and built to fit either a 100 kN or a 250 kN load frame. Flexural strength value, cycles to failure, and failure mode results from submerged fatigue testing will be used to inform marine energy structure designs. The coupon-scale test method will be used to scale up to and inform methods for subsequent subcomponent testing and standards development. The benefits of designing marine energy structures to informed standards are decreased lifetime costs and increased reliability and energy production, ultimately leading to a sustainable and low-carbon energy system.
Marine energy structures are typically made of advanced composite materials and are subjected to extreme ocean environments in service. In extreme ocean environments, seawater currents and waves load structures repeatedly, which cause two environmental conditions: water intrusion and mechanical fatigue. In prior research, the two environmental conditions were applied sequentially, where composite specimens were aged and then mechanically tested. To understand the combined effects of dynamic loading and water intrusion on composite materials, the present study involves the static and fatigue four-point bend testing of composite coupons in a water tank. The water tank was designed and built to fit either a 100 kN or a 250 kN load frame. Flexural strength value, cycles to failure, and failure mode results from submerged fatigue testing will be used to inform marine energy structure designs. The coupon-scale test method will be used to scale up to and inform methods for subsequent subcomponent testing and standards development. Finally, the benefits of designing marine energy structures to informed standards are decreased lifetime costs and increased reliability and energy production, ultimately leading to a sustainable and low-carbon energy system.
Marine energy structures are typically made of advanced composite materials and are subjected to extreme ocean environments in service. In extreme ocean environments, seawater currents and waves load structures repeatedly, which cause two environmental conditions: water intrusion and mechanical fatigue. In prior research, the two environmental conditions were applied sequentially, where composite specimens were aged and then mechanically tested. To understand the combined effects of dynamic loading and water intrusion on composite materials, the present study involves the static and fatigue four-point bend testing of composite coupons in a water tank. The water tank was designed and built to fit either a 100 kN or a 250 kN load frame. Flexural strength value, cycles to failure, and failure mode results from submerged fatigue testing will be used to inform marine energy structure designs. The coupon-scale test method will be used to scale up to and inform methods for subsequent subcomponent testing and standards development. The benefits of designing marine energy structures to informed standards are decreased lifetime costs and increased reliability and energy production, ultimately leading to a sustainable and low-carbon energy system.
Marine energy structures are typically made of advanced composite materials and are subjected to extreme ocean environments in service. In extreme ocean environments, seawater currents and waves load structures repeatedly, which cause two environmental conditions: water intrusion and mechanical fatigue. In prior research, the two environmental conditions were applied sequentially, where composite specimens were aged and then mechanically tested. To understand the combined effects of dynamic loading and water intrusion on composite materials, the present study involves the static and fatigue four-point bend testing of composite coupons in a water tank. The water tank was designed and built to fit either a 100 kN or a 250 kN load frame. Flexural strength value, cycles to failure, and failure mode results from submerged fatigue testing will be used to inform marine energy structure designs. The coupon-scale test method will be used to scale up to and inform methods for subsequent subcomponent testing and standards development. The benefits of designing marine energy structures to informed standards are decreased lifetime costs and increased reliability and energy production, ultimately leading to a sustainable and low-carbon energy system.
Composite materials are being considered for the tankage of cryogenic propellants in access to space because of potentially lower structural weights. A major hurdle for composites is an inherent concern about the safety of using flammable structural materials in contact with liquid and gaseous oxygen. A hazards analysis approach addresses a series of specific concerns that must be addressed based upon test data. Under the 2nd Generation Reusable Launch Vehicle contracts, testing was begun for a variety of organic matrix composite materials both to aid in the selection of materials and to provide needed test data to support hazards analyses. The work has continued at NASA MSFC and the NASA WSTF to provide information on the potential for using composite materials in oxygen systems. Appropriate methods for oxygen compatibility testing of structural materials and data for a range of composite materials from impact, friction, flammability and electrostatic discharge testing are presented. Remaining concerns and conclusions about composite tank structures, and recommendations for additional testing are discussed. Requirements for system specific hazards analysis are identified.
As part of the NASA Cryogenic Propellant Storage and Transfer (CPST) Engineering Design Unit (EDU) testing with liquid hydrogen, screen-channel liquid acquisition devices (LADs) were tested during liquid hydrogen outflow from the EDU tank. A stainless steel screen mesh (325x2300 Dutch T will weave) was welded to a rectangular cross-section channel to form the basic LAD channel. Three LAD channels were tested, each having unique variations in the basic design. The LADs fed a common outflow sump at the aft end of the 151 cu. ft. volume aluminum tank, and included a curved section along the aft end and a straight section along the barrel section of the tank. Wet-dry sensors were mounted inside the LAD channels to detect when vapor was ingested into the LADs during outflow. The use of warm helium pressurant during liquid hydrogen outflow, supplied through a diffuser at the top of the tank, always led to early breakdown of the liquid column. When the tank was pressurized through an aft diffuser, resulting in cold helium in the ullage, LAD column hold-times as long as 60 minutes were achieved, which was the longest duration tested. The highest liquid column height at breakdown was 58 cm, which is 23 less than the isothermal bubble-point model value of 75 cm. This paper discusses details of the design, construction, operation and analysis of LAD test data from the CPST EDU liquid hydrogen test.
Tests were made in the NACA tank and in the NACA 7 by 10 foot wind tunnel on two models of transverse step floats and three models of pointed step floats considered to be suitable for use with single float seaplanes. The object of the program was the reduction of water resistance and spray of single float seaplanes without reducing the angle of dead rise believed to be necessary for the satisfactory absorption of the shock loads. The results indicated that all the models have less resistance and spray than the model of the Mark V float and that the pointed step floats are somewhat superior to the transverse step floats in these respects. Models 41-D, 61-A, and 73 were tested by the general method over a wide range of loads and speeds. The results are presented in the form of curves and charts for use in design calculations.