This brief overview introduced the symposium session on microgravity fluid acquisition and transfer. It states the objective of NASA efforts in this technology and the approach being taken in the technology program. The problems are outlined and various methods for low-gravity fluid acquisition and transfer are summarized. Applications for the technology are described and an assessment of the current state of the art is presented. NASA and DOD on-going and planned programs are listed

Meserole, Jere S.

English

NASA Technical Reports Server

N87-21146
OVERVIEW
FLUID ACQUISITION AND TRANSFER
Jere S. Meserole
Boeing Aerospace Company
Seattle, Washington
This brief overview introduced the symposium session on microgravity fluid
acquisition and transfer. It states the objective of NASA efforts in this
technology and the approach being taken in the technology program. The
problems are outlined and various methods for low-gravity fluid acquisition
and transfer are summarized. Applications for the technology are described
and an assessment of the current state of the art is presented. NASA and
DoD on-going and planned programs are listed.
_C¢"_|NG PACE D_..A_ _OT F_it/:_D
57
https://ntrs.nasa.gov/search.jsp?R=19870011713 2020-03-20T12:00:22+00:00Z
INTRODUCTION
The overall objective of NASA efforts in microgravity fluid management is
to develop the technology required for efficientfluidsystems in space. The
technology is applicable to both cryogenic and space-storable liquids,but
current research emphasizes technology for managing cryogenic propellants,
since there is littleproven technology for in-space handling of cryogens.
The research efforts include analysis, computer code development, and
experiments. Verification of the anlytJcal models and the codes is an
important element of the program.
This session of the symposium emphasizes issues pertaining to liquid
acquisition and transfer in microgravity, although many of the papers
present research results that are equally important to in-space fluid
storage. The term "acquisition"encompasses allmethods for positioningthe
liquidcontents of a storage tank at the tank outlet and ensuring vapor-free
extraction of the liquid. "Transfer" includes all aspects of fillingone tank
(e.g.,a vehicle propellant tank or a storage tank) from another while in
orbit.
Low-Gravity Fluid Acquisition
and Transfer Technology
Overall Objective:
General Approach:
Provide technology to enable design of efficient
systems for managing fluids in the space
environment
Perform experiments to verify analytical models
and scaling techniques
Acquisition = Positioning liquidat the tank outletfor withdrawal
Transfer = On-orbit tank fill or refill. Includes:
• Supply tank pressurization
• Receiver tank pressure control
• Chilldown
• Venting
Figure 1
58
APPLICATIONS
Applications for microgravity fluid management technology will include
(1) propellant management in launch vehicle upper stages and orbiters;
(2) on-orbit fueling of satellites and propulsion stages (including the Orbital
Maneuvering Vehicle and the Orbital Transfer Vehicle), so they can be
designed for launch without the loads associated with on-board propellant
and/or for space-based reuse; (3) replenishing fluid subsystems on the Space
Station; (4)resupplying propellant and other liquid consumables on space
experiments and satellites to extend their service lives; and (5) supplying the
liquids required for operation of space-based lasers, particle beam weapons,
and other military platforms.
Potential Applications
• Earth-to-orbit transport vehicles
• On-orbit fueling of satellitesand propulsion stages
• Space Station subsystems replenishment
• Experiment and satellitefluidresupply
• Resupply ofreactants, fuels,coolants,and propellants
forspace-based directed-energy weapons
Figure 2
59
FLUID ACQUISITION AND TRANSFER METHODS
Many methods exist for liquid acquisition in low gravity and several have
been demonstrated in practice. Some are used routinely in operational
vehicles and satellites. The needs for further research and development rest
principally in the areas of cryogenic fluid management and systems
reusability. Four general approaches to liquid acquisition that are suitable
for cryogens are (1)propulsive settling, (2) start baskets, (3) screened
channels, and (4) vanes. The first two are applicable to vehicles and the last
two to mierogravity fluid transfer. The design of acquisition devices is
particularly difficult for liquid hydrogen, because of its low surface tension
and relative ease of vaporization.
Screened channels forming what is ealIed a total-communication liquid
acquisition device will likely be the approach used in on-orbit cryogen
storage tanks. Vane systems cannot reliably position low-surface-tension
fluids in the presence of disturbances. No significant low-gravity
acquisition and transfer data has yet been obtained for liquid hydrogen and
oxygen.
Liquid Acquisition
I I II
r
Figure 3
5O
Methods for fluid transfer in mierogravity can be classified as one of two
general approaches: fluid dynamic or thermodynamic. The difference
between them is in how the problem of venting the receiver tank ullage is
handled. With the fluid dynamic approach, smMl acceleration forces (e.g.,
from vehicle drag, tethering, or small thrusters) or surface-tension liquid
positioning devices are used to orient the liquid contents of the tank away
from the vent. The liquid inflow rate must be small to avoid breaking up the
liquid-vapor interface.
With thermodynamic approach, the ullage is compressed and condensed using
the cool incoming liquid as a heat sink for the heat of condensation. This is
the favored approach for cryogens. It avoids the need for venting during all
but the ehilldown phase of the transfer process. With a tank that is initially
empty and warm, first a small amount of liquid is admitted to the tank,
allowed to vaporize and chill the tank, and then vented.
Fluid Transfer
Fluid dynamic approach Thermodynamic approach
Vented fill with ullage
positioning and/or
active phase separation
/
No-vent fill with prechill
and vent, refrigeration,
and/or ullage compression
Figure 4
61
STATE OF THE ART
The state of the art in liquid acquisition comprises space-proven,
operational components for noncryogenic liquidsbut only unproven concepts
for cryogens. Some normal-gravity laboratory tests have been conducted
with small-scale cryogen systems. Microgravity flight experience with
cryogen surface-tension liquidacquisitiondevices, slosh control, autogenous
tank pressurization systems, and mass gaging is virtually nonexistent.
Numerical modeling capability for microgravity fluid motion and
thermodynamics is under development. One code developed for the NASA
Lewis Research Center (calledNASA-VOF2D) has justbecome available.
State-of-the-Art Assessment- Liquid Acquisition
I I I
• Surface-tension liquid acquisition devices
• Flight experience with noncryogenic liquids (no performance data)
• Small cryogenic system tests and screen characterization studies
conducted in laboratory environment
• Fluid dynamic behavior
• Some limited flight experience
• Analytical correlations based on drop tower experiments
• Numerical modeling capability under development
• Pressurization systems
• Orbital data has been used to establish correlatingparameters for
high liquid outflow rate helium pressurant systems
• Limited experience with autogenous pressurant systems
• Mass gaging instrumentation
• Flight experience with noncryogenic liquid
• Seek and develop activityunderway at JSC
Figure 5
62
On-orbit transfer of a noncryogenie liquid (hydrazine) has been
demonstrated on the Shuttle, and an operational system is under
development at the Johnson Space Center (JSC) as part of the Orbital
Spacecraft Consumables Resupply Systems program. Considerable activity
is underway at NASA in conjunction with the Space Station program and
within the military (e.g., the spacecraft Assembly, Maintenance, and
Servicing study) to identify systems requirements for fluid resupply
operations and to develop the necessary automation and robotics.
For cryogens, the data available is nearly all from ground-based testing.
Some small-scale low-gravity data for liquidnitrogen was obtained in the
NASA LeRC 5-second drop tower. On orbit test data for tank chill,no-vent
fill,autogenous pressurization,fluid metering, line connect and disconnect,
and leak detection are necessary.
State-of-the-Art Assessment- Fluid Transfer
• Transfer line and receiver tank chilldown
• Analytical models and experimental data available for
cryogen systems in normal gravity
• Limited data obtained with LN2 in NASA drop tower
• No-vent fill
• Limited IR&D laboratory testing performed
• Fluid mass and quality metering
• Limited cryogenic IR&D laboratory testing performed
• Quick disconnect
• Development activityfor space application,includin_
instrumentation forleak detection,recommended by _STSC
Figure 6
63
NASA AND DOD PROGRAMS
Several NASA and Department of Defense research programs and studies
are addressing issues pertaining to microgravity fluid management. Few of
them involve hardware at present, but many are concept and design studies
intended to evolve into hardware development.
The NASA Cryogenic Fluid Management Flight Experiment program, for
example, is currently designing a sophisticated space experiment for
demonstrating technology and methods for storing and transferring liquid
hydrogen. Studies of space tethers and of shuttle external tank propellant
scavenging may lead to space experiments relatively soon. The Space
Infrared Telescope Facility will require helium and propellant resupply.
Two-phase thermal transport loops for the Space Station require technology
for fluidhandling. The Air Force Rocket Propulsion Laboratory isbeginning
a hardware development program for toroidal tanks for cryogenic upper
stages and isplanning a fluidmanagement space experiment.
Current and Planned Programs
- NASA and DOD
• Cryogenic Fluid Management Flight Experiment
• Orbital Transfer Vehicle
• Orbital Maneuvering Vehicle
• Shuttle propellant scavenging
• Space tethers
• Space Infrared Telescope Facility
• Mass gaging
• Space Station thermal control technology
• Storable Fluid Management Demonstration
• Orbital Spacecraft Consumables Resupply Systems
• Long-Term Cryogen Test Bed
• Helium Transfer Experiment
• Compact LOX Feedsystem (RPL)
• Fluid Management Flight Experiment (RPL)
Figure 7
64
SUMMARY
The needs for acquiring data on fluid behavior in microgravity and to
demonstrate concepts and technology are well characterized. Some ground
testing is on-going at NASA, in the military, and in industry, but normal-
gravity experiments cannot in many circumstances adequately simulate
important microgravity phenomena.
The papers in this section describe several current studies intended to lead
eventually to space experiments. Among the topics covered are numerical
modeling, fluid slosh and fluid-vehicle dynamic interaction, mass gaging, jet
mixing and ullage condensation, the Cryogenic Fluid Management Flight
Experiment, and methods for managing superfluid helium in microgravity.
References
.
.
.
.
5_
o
Q
Aydelott, J. C.; Carney, M. J.; And Hochstein, J.I.: NASA Lewis
Research Center Low-Gravity Fluid Management Technology Program.
AIAA/GNOS Paper 85-002, NASA TM 87145, November 1985.
Aydelott, J. C.: Technology Requirements to be Addressed by the
NASA Lewis Research Center Cryogenic Fluid Management Facility
Program. AIAA Paper 85-1229, July 1985.
Aydelott, J. C.; Gille, J. P.; and Eberhardt, R. N.: On Orbit
Cryogenic Fluid Transfer. AIAA Paper 84-1343, NASA TM 83688,
June 1984.
Eberhardt, R. N.; and Fester, D. A.: Orbital Fluid Management.
AIAA Paper 85-1234, July 1985.
Gille,J. P.: Analysis and Modeling of Fluid Transfer in Orbit.
AIAA Paper 86-1718, June 1986.
Rollins,J. R.; Grove, R. K.; and Jaekle, D. E.: Twenty-Three Years
of Surface Tension Propellant Management System Design,
Development, Manufacture, Test, and Operation. AIAA Paper 85-
1199, July 1985.
Stark, J. A.: Low-g Fluid Transfer Technology Study. (CASD-NAS-76-
017, General Dynamics/Convair; Contract NAS3-17814), NASA CR-
135020, 1976.
65



Overview: Fluid acquisition and transfer

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server