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Technical Paper

Thermal Modeling of Engine Components for Temperature Prediction and Fluid Flow Regulation

2001-03-05
2001-01-1014
The operation of internal combustion engines depend on the successful management of the fuel, spark, and cooling processes to ensure acceptable performance, emission levels, and fuel economy. Two different thermal management systems exist for engines - air and liquid cooling. Smaller displacement utility and spark ignition aircraft engines typically feature air cooled systems which rely on forced convection over the exterior engine surfaces. In contrast, passenger/light-duty engines use a water-ethylene glycol mixture which circulates through the radiator, water pump, and heater core. The regulation of the overall engine temperature, based on the coolant's temperature, has been achieved with the thermostat valve and (electric) radiator fan. To provide insight into the thermal behavior of the cylinder-head assembly for enhanced cooling system operation, a dynamic model must exist.
Technical Paper

Energy Analysis of an Enclosed, Long-Duration Planetary Habitat Test-Bed

1998-07-13
981711
An energy balance was performed on the life support equipment used during the Phase III, 90-day, human Lunar-Mars Life Support Test Project at the Johnson Space Center. The purpose of the analysis was to account for all the energy sources, uses, and losses in the test-bed. Knowledge from this task may allow more energy efficient designs to be developed. Control volumes were defined and energy balance equations were generated for major systems. The analyses succeeded in balancing the energy fairly well for several systems. Further, the data showed that inefficiencies existed, and means of design optimization were subsequently suggested.
Technical Paper

High Temperature Lift Heat Pump Refrigerant and Thermodynamic Cycle Selection

1994-06-01
941272
This paper describes the process and analysis used to select a refrigerant and thermodynamic cycle as the basis of a vapor compression heat pump requiring a high temperature lift. Use of a vapor compression heat pump versus other types was based on prior work performed for the Electric Power Research Institute. A high lift heat pump is needed to enable a thermal control system to remove heat down to 275K from a habitable volume when the external thermal environment is severe. For example, a long term habitat will reject heat from a space radiator to a 325K environment. The first step in the selection process was to perform an optimization trade study, quantifying the effect of radiator operating temperature and heat pump efficiency on total system mass; then, select the radiator operating temperature corresponding to the lowest system mass. Total system mass included radiators, all heat pump components and the power supply system.
Technical Paper

Oxygen From Lunar Soils

1996-07-01
961595
We have conducted experiments on 16 lunar soils and 3 lunar volcanic glass samples to study the extraction of oxygen, an important resource for future lunar bases. The samples were chosen to span the range of composition and mineralogy represented in the Apollo collection. Each sample was reduced in flowing hydrogen for 3 hours at 1050°C. The dominant effect was reduction of Fe2+ (as FeO) in minerals and glass to iron metal, with concomitant release of oxygen. Oxygen extraction was strongly correlated with initial Fe2+ abundance but varied among mineral and glass phases. The experimental reduction of lunar soil and glass provides a method for assessing the oxygen production potential for sites on the lunar surface from lunar orbit. Our results show that oxygen yield from lunar soils can be predicted from knowledge of only one parameter, total iron content. This parameter can be measured from orbit by gamma ray spectrometry or multispectral imaging.
Technical Paper

Dehumidification Via Membrane Separation for Space-Based Applications

1988-07-01
881037
This paper describes the development of a membrane-based dehumidification process for space-based applications, such as spacecraft cabins and extra-vehicular-activity (EVA) space suits. Results presented are from 1) screening tests conducted to determine the efficacy of various membranes to separate water vapor from air, and 2) parametric and long-term tests of membranes operated at conditions that simulate the range of environmental conditions (e.g., temperature and relative humidity [RH]) expected in the planned space station. Also included in this paper is a discussion of preliminary designs of membrane-based dehumidification processes for the space station and EVA space suits. These designs result in compact and energy-efficient systems that offer significant advantages over conventional dehumidification processes.
Technical Paper

Design of a Water Electrolysis Flight Experiment

1993-07-01
932087
Supply of oxygen (O2) and hydrogen (H2) by electrolyzing water in space will play an important role in meeting the National Aeronautics and Space Administration's (NASA's) needs and goals for future space missions. Both O2 and H2 are envisioned to be used in a variety of processes including crew life support, spacecraft propulsion, extravehicular activity, electrical power generation/storage as well as in scientific experiment and manufacturing processes. Life Systems, Inc., in conjunction with NASA, has been developing an alkaline-based Static Feed Electrolyzer (SFE). During the development of the water electrolysis technology over the past 23 years, an extensive engineering and scientific data base has been assembled.
Technical Paper

Integrated Atmosphere Revitalization System Description and Test Results

1983-07-11
831110
Regenerative-type subsystems are being tested at JSC to provide atmosphere revitalization functions of oxygen supply and carbon dioxide (CO2) removal for a future Space Station. Oxygen is supplied by an electrolysis subsystem, developed by General Electric, Wilmington, Mass., which uses the product water from either the CO2 reduction subsystem or a water reclamation process. CO2 is removed and concentrated by an electrochemical process, developed by Life Systems, Inc., Cleveland, Ohio. The concentrated CO2 is reduced in a Sabatier process with the hydrogen from the electrolysis process to water and methane. This subsystem is developed by Hamilton Standard, Windsor Locks, Conn. These subsystems are being integrated into an atmosphere revitalization group. This paper describes the integrated test configuration and the initial checkout test. The feasibility and design compatibility of these subsystems integrated into an air revitalization system is discussed.
Technical Paper

An Advanced Carbon Reactor Subsystem for Carbon Dioxide Reduction

1986-07-14
860995
Reduction of metabolic carbon dioxide is one of the essential steps in physiochemical air revitalization for long-duration manned space missions. Under contract with NASA Johnson Space Center, Hamilton Standard is developing an Advanced Carbon Reactor Subsystem (ACRS) to produce water and dense solid carbon from carbon dioxide and hydrogen. The ACRS essentially consists of a Sabatier Methanation Reactor (SMR) to reduce carbon dioxide with hydrogen to methane and water, a gas-liquid separator to remove product water from the methane, and a Carbon Formation Reactor (CFR) to pyrolyze methane to carbon and hydrogen. The hydrogen is recycled to the SMR, while the produce carbon is periodically removed from the CFR. The SMR is well-developed, while the CFR is under development. In this paper, the fundamentals of the SMR and CFR processes are presented and results of Breadboard CFR testing are reported.
Technical Paper

Further Characterization and Multifiltration Treatment of Shuttle Humidity Condensate

1995-07-01
951685
On the International Space Station (ISS), humidity condensate will be collected from the atmosphere and treated by multifiltration to produce potable water for use by the crews. Ground-based development tests have demonstrated that multifiltration beds filled with a series of ion-exchange resins and activated carbons can remove many inorganic and organic contaminants effectively from wastewaters. As a precursor to the use of this technology on the ISS, a demonstration of multifiltration treatment under microgravity conditions was undertaken. On the Space Shuttle, humidity condensate from cabin air is recovered in the atmosphere revitalization system, then stored and periodically vented to space vacuum. A Shuttle Condensate Adsorption Device (SCAD) containing sorbent materials similar to those planned for use on the ISS was developed and flown on STS-68 as a continuation of DSO 317, which was flown initially on STS-45 and STS-47.
Technical Paper

Ventilation Transport Trade Study for Future Space Suit Life Support Systems

2008-06-29
2008-01-2115
A new and advanced portable life support system (PLSS) for space suit surface exploration will require a durable, compact, and energy efficient system to transport the ventilation stream through the space suit. Current space suits used by NASA circulate the ventilation stream via a ball-bearing supported centrifugal fan. As NASA enters the design phase for the next generation PLSS, it is necessary to evaluate available technologies to determine what improvements can be made in mass, volume, power, and reliability for a ventilation transport system. Several air movement devices already designed for commercial, military, and space applications are optimized in these areas and could be adapted for EVA use. This paper summarizes the efforts to identify and compare the latest fan and bearing technologies to determine candidates for the next generation PLSS.
Technical Paper

Cascade Distillation Subsystem Development Testing

2008-06-29
2008-01-2195
Recovery of potable water from wastewater is essential for the success of long-term manned missions to the moon and Mars. Honeywell International and the team consisting of Thermodistillation Company (Kyiv, Ukraine) and NASA Johnson Space Center (JSC) Crew and Thermal Systems Division are developing a wastewater processing subsystem that is based on centrifugal vacuum distillation. The Wastewater Processing Cascade Distillation Subsystem (CDS) utilizes an innovative and efficient multi-stage thermodynamic process to produce purified water. The rotary centrifugal design of the system also provides gas/liquid phase separation and liquid transport under microgravity conditions. A five-stage prototype of the subsystem was built, delivered and integrated into the NASA JSC Advanced Water Recovery Systems Development Facility for development testing.
Technical Paper

A Review of Spark-Ignition Engine Air Charge Estimation Methods

2016-04-05
2016-01-0620
Accurate in-cylinder air charge estimation is important for engine torque determination, controlling air-to-fuel ratio, and ensuring high after-treatment efficiency. Spark ignition (SI) engine technologies like variable valve timing (VVT) and exhaust gas recirculation (EGR) are applied to improve fuel economy and reduce pollutant emissions, but they increase the complexity of air charge estimation. Increased air-path complexity drives the need for cost effective solutions that produce high air mass prediction accuracy while minimizing sensor cost, computational effort, and calibration time. A large number of air charge estimation techniques have been developed using a range of sensors sets combined with empirical and/or physics-based models. This paper provides a technical review of research in this area, focused on SI engines.
Technical Paper

Physics-Based Exhaust Pressure and Temperature Estimation for Low Pressure EGR Control in Turbocharged Gasoline Engines

2016-04-05
2016-01-0575
Low pressure (LP) and cooled EGR systems are capable of increasing fuel efficiency of turbocharged gasoline engines, however they introduce control challenges. Accurate exhaust pressure modeling is of particular importance for real-time feedforward control of these EGR systems since they operate under low pressure differentials. To provide a solution that does not depend on physical sensors in the exhaust and also does not require extensive calibration, a coupled temperature and pressure physics-based model is proposed. The exhaust pipe is split into two different lumped sections based on flow conditions in order to calculate turbine-outlet pressure, which is the driving force for LP-EGR. The temperature model uses the turbine-outlet temperature as an input, which is known through existing engine control models, to determine heat transfer losses through the exhaust.
Technical Paper

Assessment of Model-Based Knock Prediction Methods for Spark-Ignition Engines

2017-03-28
2017-01-0791
Knock-limited engine operation is one of the most important constraints on fuel efficiency and performance that must be considered during the design, control algorithm development and calibration of spark-ignition engines. This research evaluates the accuracy of model-based knock prediction routines and their applicability for control-oriented applications over various engine operating conditions using commercial fuels. Two common methods of knock prediction, a generalized chemical kinetics model and an empirical induction-time correlation, are evaluated and compared against experimental data. The experimental investigation is conducted using a naturally aspirated 3.6L V6 engine, retrofitted with cooled Exhaust Gas Recirculation (EGR). Data are acquired from spark timing sweeps under knocking conditions at different engine speeds and loads in an engine dynamometer cell.
Technical Paper

Multifunctional Fiber Batteries for Next Generation Space Suits

2007-07-09
2007-01-3173
As next generation space suit concepts enable extravehicular activity (EVA) mission capability to extend beyond anything currently available today, revolutionary advances in life support technologies are required to achieve anticipated NASA mission profiles that may measure years in duration and require hundreds of sorties. Since most life support systems require power, increased mass and volume efficiency of the energy storage materials can have a dramatic impact on reducing the overall weight of next generation space suits. This paper details the development of a multifunctional fiber battery to address these needs.
Technical Paper

Continuously Regenerable Freeze-Out CO2 Control Technology

2007-07-09
2007-01-3270
Carbon dioxide (CO2) removal technology development for portable life support systems (PLSS) has traditionally concentrated in the areas of solid and liquid chemical sorbents and semi-permeable membranes. Most of these systems are too heavy in gravity environments, require prohibitive amounts of consumables for operation on long term planetary missions, or are inoperable on the surface of Mars due to the presence of a CO2 atmosphere. This paper describes the effort performed to mature an innovative CO2 removal technology that meets NASA's planetary mission needs while adhering to the important guiding principles of simplicity, reliability, and operability. A breadboard cryogenic carbon dioxide scrubber for an ejector-based cryogenic PLSS was developed, designed, and tested. The scrubber freezes CO2 and other trace contaminants out of expired ventilation loop gas using cooling available from a liquid oxygen (LOX) based PLSS.
Technical Paper

A User Configurable Powertrain Controller with Open Software Management

2007-04-16
2007-01-1601
The emphasis on vehicle fuel economy and tailpipe emissions, coupled with a trend toward greater system functionally, has prompted automotive engineers to develop on-board control systems with increased requirements and complexity. Mainstream engine controllers regulate fuel, spark, and other subsystems using custom solutions that incorporate off-the-shelf hardware components. Although the digital processor core and the peripheral electronics may be similar, these controllers are targeted to fixed engine architectures which limit their flexibility across vehicle platforms. Moreover, additional software needs are emerging as electronics continue to permeate the ground transportation sector. Thus, automotive controllers will be required to assume increased responsibility while effectively communicating with distributed hardware modules.
Technical Paper

Advanced Thermal Management for Internal Combustion Engines - Valve Design, Component Testing and Block Redesign

2006-04-03
2006-01-1232
Advanced engine cooling systems can enhance the combustion environment, increase fuel efficiency, and reduce tailpipe emissions with less parasitic engine load. The introduction of computer controlled electro-mechanical valves, radiator fans, and coolant pumps require mathematic models and real time algorithms to implement intelligent thermal control strategies for prescribed engine temperature tracking. Smart butterfly valves can replace the traditional wax-based thermostat to control the coolant flow based on both engine temperature and operating conditions. The electric water pump and radiator fan replace the mechanically driven components to reduce unnecessary engine loads at high speeds and provide better cooling at low speeds.
Technical Paper

On-Orbit Performance of the Major Constituent Analyzer

2002-07-15
2002-01-2404
The Major Constituent Analyzer (MCA) was activated on-orbit on 2/13/01 and provided essentially continuous readings of partial pressures for oxygen, nitrogen, carbon dioxide, methane, hydrogen and water in the ISS atmosphere. The MCA plays a crucial role in the operation of the Laboratory ECLSS and EVA operations from the airlock. This paper discusses the performance of the MCA as compared to specified accuracy requirements. The MCA has an on-board self-calibration capability and the frequency of this calibration could be relaxed with the level of instrument stability observed on-orbit. This paper also discusses anomalies the MCA experienced during the first year of on-orbit operation. Extensive Built In Test (BIT) and fault isolation capabilities proved to be invaluable in isolating the causes of anomalies. The process of fault isolation is discussed along with development of workaround solutions and implementation of permanent on-orbit corrections.
Technical Paper

BIO-Plex Thermal Control System Design

2001-07-09
2001-01-2324
Engineers at the Johnson Space Center (JSC) are using innovative strategies to design the TCS for the Bio-regenerative Planetary Life Support Systems Test Complex (BIO-Plex), a regenerative advanced life support system ground test bed. This paper provides a current description of the BIO-Plex TCS design, testing objectives, analyses, descriptions of the TCS test articles expected to be tested in the BIO-Plex, and forward work regarding TCS. The TCS has been divided into some subsystems identified as permanent “infrastructure” for the BIO-Plex and others that are “test articles” that may change from one test to the next. The infrastructure subsystems are the Heating, Ventilation and Air-Conditioning (HVAC), the Crew Chambers Internal Thermal Control Subsystem (CC ITCS), the Biomass Production Chamber Internal Thermal Control Subsystem (BPC ITCS), the Waste Heat Distribution Subsystem (WHDS) and the External Thermal Control Subsystem (ETCS).
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