Water hammer in a spacecraft propellant feed system

The Global Precipitation Measurement (GPM) mission is an international partnership between NASA and JAXA whose Core spacecraft performs cutting-edge measurements of rainfall and snowfall worldwide and unifies data gathered by a network of precipitation measurement satellites. The Core spacecraft's propulsion system is a blowdown monopropellant system with an initial hydrazine load of 545 kg in a single composite overwrapped propellant tank. At launch, the propulsion system contained propellant in the tank and manifold tubes upstream of the latch valves, with low-pressure helium gas in the manifold tubes downstream of the latch valves. The system had a relatively high beginningof-life pressure and long downstream manifold lines; these factors created conditions that were conducive to high surge pressures. This paper discusses the GPM project's approach to surge mitigation in the propulsion system design. The paper describes the surge testing program and results, with discussions of specific difficulties encountered. Based on the results of surge testing and pressure drop analyses, a unique configuration of cavitating venturis was chosen to mitigate surge while minimizing pressure losses during thruster maneuvers. This paper concludes with a discussion of overall lessons learned with surge pressure testing for NASA Goddard spacecraft programs.

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“…6. The method calculates a water-to-hydrazine relation based on density, bulk modulus of elasticity, and tubing properties.…”

Section: Water-to-hydrazine Conversionmentioning

confidence: 99%

Surge Pressure Mitigation in the Global Precipitation Measurement Mission Core Propulsion System

Scroggins¹,

Fiebig²

2014

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

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“…The experimental facility used in the present study is basically designed to reproduce the priming procedure in satellites [14,15,16,17,18,19,10,11], including all the elements of a satellite propulsion system involved in the fluid hammer occurrence, i.e. a pressurized liquid tank, a fast opening valve (FOV), consisting of a ball valve with a pneumatic actuator, and a 2 m pipe line referred to as "test element".…”

Section: Experimental Facilitymentioning

confidence: 99%

Analysis of fluid hammer occurrence with phase change and column separation due to fast valve opening by means of flow visualization

Lema

Peña

Buchlin

et al. 2016

Experimental Thermal and Fluid Science

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“…Where P wh is peak water hammer pressure ρ is fluid density c is fluid speed of sound u is fluid velocity Equation (1) assumes that the transient event, such as a valve opening or closing, occurs instantaneously or quickly enough that it is effectively instantaneous. Because ρ and c are properties of the fluid, Eq.…”

Section: Introductionmentioning

confidence: 99%

A Streamlined Approach to Venturi Sizing

Scroggins¹

2012

48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference &Amp;amp; Exhibit

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Many spacecraft propulsion systems use orifices or cavitating venturis to mitigate water hammer pressure spikes, but the current process for sizing and validating these devices is time-consuming. This paper discusses the effort to find a relationship between peak water hammer pressure and venturi throat diameter that can be used to shorten the amount of time required to size venturis for flight. The venturi throat diameter must be chosen carefully to minimize pressure drop at steady-state flight flow rates for thruster burns but still provide components enough protection from damaging pressure spikes. At NASA Goddard Space Flight Center, cavitating venturis are sized through testing alone. Depending on the complexity of the system and the number of venturis being tested, water hammer testing can take months of engineer and technician time. Standard sets of water hammer tests were performed using venturis with throat diameters ranging from 0.035" to 0.080", located in both the simplest representative system that could be created -a straight line setup, as well as a system that is slightly more complex -a single branch was added to the straight line setup. Both setups included a flight-like latch valve used to mimic flight scenarios, such as system priming, and dynamic pressure transducers to record pressure surges in locations of concern, chosen by investigating test data from previous missions. Each setup was also tested without a venturi or other dedicated pressure surge mitigation device. The experimental data from this testing resulted in a simple scaling relationship between peak water hammer pressure and venturi throat diameter: the peak waterhammer pressure is proportional to the diameter of the venturi throat to the 1.5 power. This scaling relationship has the potential to significantly shorten the time and testing required to size cavitating venturis for flight propulsion systems by allowing engineers to determine an approximate venturi throat diameter based on very few water hammer tests. The testing data was compared with test data from previous GSFC missions, and the scaling relationship was found to provide conservative estimates for venturi throat size. NomenclatureAFT = Applied Flow Technology AIAA = American Institute of Aeronautics and Astronautics c = Speed of sound DR# = Dual gauge pressure regulator d vt = Venturi throat diameter Eq = Equation FO = Flow orifice FT = Forward thruster G# = Pressure gauge GHe = Gaseous Helium GPM = Global Precipitation Measurement mission GSE = Ground support equipment In = Inches k = Constant ln = Natural logarithm LPP = Low pressure panel LRO = Lunar Reconnaissance Orbiter LV = Latch valve mL/s = Milliliters per second 2 NV = Needle valve OD = Outer diameter P# = Pressure transducer psi = Pounds per square inch P wh = Peak water hammer pressure R# = Pressure regulator R 2 = Correlation coefficient RV# = Relief valve s = Seconds SDO = Solar Dynamics Observatory u = Velocity V# = Valve VP = Vacuum pump ρ = Density

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Water hammer in a spacecraft propellant feed system

Cited by 24 publications

References 1 publication

Surge Pressure Mitigation in the Global Precipitation Measurement Mission Core Propulsion System

Surge Pressure Mitigation in the Global Precipitation Measurement Mission Core Propulsion System

Analysis of fluid hammer occurrence with phase change and column separation due to fast valve opening by means of flow visualization

A Streamlined Approach to Venturi Sizing

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