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Technical Paper

Experimental Acoustic Analysis of a Motorcycle Dissipative Muffler in Presence of Mean Flow

2016-11-08
2016-32-0039
In recent years, the motorcycle muffler design is moving to dissipative silencer architectures. Due to the increased of restrictions on noise emissions, both dissipative and coupled reactive-dissipative mufflers have substituted the most widely used reactive silencers. This led to higher noise efficiency of the muffler and size reduction. A dissipative muffler is composed by a perforated pipe that crosses a cavity volume filled by a fibrous porous material. The acoustic performance of this kind of muffler are strictly dependent on the porosity of the perforated pipe and the flow resistivity characteristic of the porous material. However, while the acoustic performance of a reactive muffler is almost independent from the presence of a mean flow for typical Mach numbers of exhaust gases, in a dissipative muffler the acoustic behaviour is strictly linked to the mass flow rate intensity.
Technical Paper

Improving Fuel Economy of Thermostatic Control for a Series Plugin-Hybrid Electric Vehicle Using Driver Prediction

2016-04-05
2016-01-1248
This study investigates using driver prediction to anticipate energy usage over a 160-meter look-ahead distance for a series, plug-in, hybrid-electric vehicle to improve conventional thermostatic powertrain control. Driver prediction algorithms utilize a hidden Markov model to predict route and a regression tree to predict speed over the route. Anticipated energy consumption is calculated by integrating force vectors over the look-ahead distance using the predicted incline slope and vehicle speed. Thermostatic powertrain control is improved by supplementing energy produced by the series generator with regenerative braking during events where anticipated energy consumption is negative, typically associated with declines or decelerations.
Technical Paper

Ecology of Micro-organisms in a Small Closed System: Potential Benefits and Problems for Space Station

1989-07-01
891491
The probable sources and implications of microbial contamination on the proposed space station are discussed. Because of the limited availability of material, facilities and time on the space station, we are exploring the feasibility of replacing traditional incubation methods for assessing microbial contamination with rapid, automated methods. Some possibilities include: ATP measurement, microscopy and telecommunications, and molecular techniques such as DNA probes or monoclonal antibodies. Some of the important ecological factors that could alter microbes in space include microgravity, exposure to radiation, and antibiotic resistance.
Technical Paper

Mass Analysis for the Space Station ECLSS Using the Balance Spreadsheet Method

1989-07-01
891502
The balance spreadsheet method is applied to mass analysis of the Environmental Control and Life Support System (ECLSS). This method is used to analyze the requirements for ECLSS carbon dioxide, latent water, crew potable water, crew hygiene water, crew hygiene waste water, crew urinal water, crew waste water, animal potable water, animal hygiene water, hydrogen, oxygen, nitrogen, and various solid wastes. The spreadsheet layout reduces the complexity of the ECLSS analysis by concisely defining the sources, sinks, and net changes in mass for each fluid. This approach also builds the data base by assigning an area for time-independent data and another one for time-dependent data so that layout modifications and formula implementations can be easily accomplished. The analysis method is illustrated by using information from the latest Space Station ECLSS Architectural Control Documents and a given Space Station assembly sequence. The analysis results are plotted and discussed.
Technical Paper

A Space Station Extravehicular Mobility Unit Computer Simulation

1989-07-01
891501
A computer simulation model is a valuable tool in the evaluation of a developing hardware program and as a diagnostic/simulation aid for an ongoing production system. Hamilton Standard has developed a G189A simulation model to investigate the performance of a Space Station Extravehicular Mobility Unit (SSEMU). The SSEMU, also known as the Advanced Extravehicular Mobility Unit (AEMU), is in a hardware selection phase and further studies are beneficial to evaluate system performance using various subsystem candidates and integration schemes. Several subroutines representing newly developed subsystems have been Incorporated Into G189A for use in this model. These subroutines are: a Thermoelectric Condensing Heat Exchanger, a Regenerable Non-venting Thermal Sink, a Metal Oxide CO2 Removal/Dehumidification Subsystem, and the air Interactions In the suit volume.
Technical Paper

System Level Design Analyses for the Space Station Environmental Control and Life Support System

1989-07-01
891500
Computer model analysis is an integral part of the space station Environmental Control and Life Support System (ECLSS) development program. Systems level computer models are being developed to address key parameters in the design of the Air Revitalization (AR), Temperature and Humidity Control (THC), and Atmosphere Control and Supply (ACS) subsystems of the space station ECLSS. The models are being used to resolve design issues related to appropriate control methodology, flow distribution schemes, and optimum sequencing of the AR, THC, and ACS components. The Computer Aided Systems Engineering and Analysis (CASE/A) program, in continuing development at the Marshall Space Flight Center (MSFC), is being used to develop these models. Data made available through hardware testing at the MSFC Core Module Integration Facility (CMIF) was used extensively during verification of these models.
Technical Paper

PRELIMINARY G189A COMPUTER PROGRAM MODELING OF THE SPACE STATION ECLSS

1989-07-01
891499
The initial development and subsequent evolution of the Environmental Control and Life Support System (ECLSS) for the manned Space Station requires a numerical modeling computer program that can accurately simulate the ECLSS. The G189 program has successfully provided this modeling function for the Skylab refrigeration system and for the Environmental Control System (ECS) in the Space Shuttle Orbiter. Presently being developed at Boeing Aerospace is an overall Space Station ECLSS model, which is being constructed and operated at increasing levels of complexity. This paper presents and discusses the Boeing G189A model of the baseline Space Station ECLSS. The model is in an early stage of refinement and includes all ECLSS functional operations except Fire Detection and Suppression (FDS) (which is in the detection mode only during normal Station operation) and the Avionics Air Cooling/Heating portion of the Temperature and Humidity Control (THC) Subsystem.
Technical Paper

Outfitting of the Crew Health Care System for the space Station Freedom

1989-07-01
891476
Crew medical care will be one of the most essential provisions of the space station of the 1990's. Increased duration in space, reduced crew selectivity, and reduced return to earth capability all speak strongly for a complete set of medical instrumentation and supplies, countermeasures for space adaptation syndrome, and the capability to closely monitor the total environment in which the crew live and work. Foreseeing these needs, NASA has committed to the development of a Crew Health Care Element for Space Station Freedom. It consists of three systems: Health Maintenance Facility, Exercise Countermeasures Facility, and Environmental Health System. For the majority of the equipment to outfit these systems, space flight ready instruments do not exist. Therefore, commercial off the shelf items will have to be converted to flight certification levels and some will even have to be modified to accommodate the microgravity conditions of Space Station Freedom.
Technical Paper

Evolution of Space Station: Life Sciences Program and Facilities

1989-07-01
891474
The needs for life sciences research and facilities on Space Station in Phase 2, based on future space exploration and utilization plans, are discussed. The assumed scenario involves a Lunar Base, manned missions to Mars, and an orbiting Space Colony for the production of Solar Power Satellites permitting replacement of fossil fuels by the middle of the next century. From this scenario, the contours of a life sciences program for the period after 1998 are derived. Based on the main elements of such a program, the major new life sciences facilities needed in Phase 2 are identified. It is concluded that a full-length dedicated life sciences module and an attached short module with large centrifuge and animal research facilities, as well as a man-rated variable research facility and other attached facilities are needed. A proposed deployment schedule for these facilities is presented.
Technical Paper

Space Station Freedom (SSF) Crew Systems SE&I

1989-07-01
891475
Space Station Program Office planning and requirements activity has accelerated during the past year to bring the Space Station Freedom Program (SSF) through the Program Requirements Review phase during 1988. The Preliminary Design Review cycle began in Jan 89, and is now planned for completion, with formal Preliminary Design Reviews (PDR), between Apr and Sept, 1990. This paper briefly describes the PROGRAMMATIC aspects of the Engineering and Integration management of the SSF Crew Systems. Emphasis is given to the the Crew Healtii Care System (CHeCS), which includes the Health Maintenance Facility (HMF), the Exercise Countermeasure Facility (ECF), and the Environmental Health System (EHS); all managed within the Man-Systems, one of die twelve “distribtuted systems.” A companion presentation in this session will detail the present status of the technology and equipments under consideration for the HMF and ECS Systems.
Technical Paper

Enabling Human Exploration of Space: A Life Sciences Overview

1989-07-01
891471
In the transition from the short-duration missions of the Space Shuttle era to long-duration exploration missions, the health and safety of crewmembers must be ensured. The body undergoes many complex physiological changes as a result of its adaptation to a microgravity environment and U.S. and Soviet experiences have shown that time is required for readaptation to gravity. The consequences of these changes for the extended exploration missions envisioned for the future are unknown. A Mars mission may require crewmembers to spend many months in microgravity, and then work effectively in a one-third gravity environment. Other problems may arise when returning crewmembers must readapt to Earth's gravity. Life Sciences activities are being planned to systematically address the physiological issues involved with long-term manned exploration missions, through ground-based studies and flight investigations on the Shuttle and Space Station Freedom.
Technical Paper

Feasibility of a Common Electrolyzer for Space Station Freedom

1989-07-01
891484
The Baseline Space Station Freedom architecture calls for separate and independent water electrolysis subsystems in ECLSS and in Propulsion. A study to assess the potential benefits and impacts of electrolyzer commonality evaluated fifteen sets of ECLSS and Propulsion architectural options with graduated levels of commonality, first by quantifying the electrical power, weight, volume, and heat rejection requirements; and then qualitatively according to safety and redundancy, reliability and maintainability, integration and verification, and assembly. There were no compelling quantitative or qualitative advantages of the options incorporating commonality which would drive a decision to alter the Baseline. The options were also compared with respect to estimated program costs. The maximum projected savings were less than five per cent, likely within the uncertainty of the estimation process.
Technical Paper

Microgravity Sensitivities For Space Station ECLS Subsystems

1989-07-01
891483
This report presents a review of the Space Station Environmental Control and Life Support subsystems (ECLSS) for sensitivity to low gravity environments. The object of this review is to categorize sensitivity areas and to quantify the risks. This review addresses all processes from a top level view and then examines in more detail those areas which were considered potential risks. The study has concentrated on the primary function of the subsystems which may be significant to the performance of the particular component and does not address integration of the subsystem and/or the mechanical aspects of the designs. The areas of primary concern were the Atmosphere Revitalization (AR), Water Recovery and Management (WRM), and the Waste Management (WM) subsystems.
Technical Paper

The Impact of the Water Recovery & Management (WRM) Subsystem Wastewater Recovery Efficiency Upon the Space Station Freedom ECLSS Water Balance

1989-07-01
891482
A parametric study of the impact of the ECLSS Water Recovery Subsystem wastewater processing efficiency upon the overall Space Station Freedom water balance was performed. In this study, a representative range of recovery efficiencies was used for each of the three different water recovery processes. The types of processes corresponded to the baseline equipment considered for potable (Multifiltration), hygiene (Reverse Osmosis), and urine/flush (Thermoelectric Integrated Membrane Evaporation Subsystem) waste water recovery. Recovery efficiencies ranging from 80 percent to 99 percent were examined, corresponding to published efficiency values available in current technical literature. The recovery efficiency associated with the hygiene wastewater reclamation process proved to be particularly significant in determining the overall Space Station Freedom ECLSS water balance because of the relatively large volume of fluid treated within this loop.
Technical Paper

Space Station Freedom Cupola Definition

1989-07-01
891525
Following the realization that adequate Space Station Freedom (see figure 1) viewing could not be achieved without breaking the plane of the modules, a conceptual design phase for the development of a cupola progressed from the idea of a small, bubble-type canopy to a much larger, two crewmember cupola. The evolving cupola conceptual designs were each evaluated against the requirements for providing a large field-of-view, a complete proximity control workstation with flexible and relocatable restraints, and sufficient volume for two, 95th percentile crewmembers to operate while still maintaining reasonable weight and size restrictions. As the SS Freedom program Preliminary Design Review draws closer, the cupola development phase shifts towards evaluation of viewing and operational capability.
Technical Paper

Zero-G Simulation using Neutral Buoyancy

1989-07-01
891529
For human beings who have been reared on the earth with its 1 G gravitational field, the condition of weightlessness is a world with which we are unfamiliar. Even if the layout and equipment configuration of a spacecraft designed to compensate for operation under Zero-G conditions, there are some things which are not effective under actual weightless conditions. In the design of a manned spacecraft, it is necessary to accumulate design data on human performance in a weightless condition, then to undertake design evaluations and verification under weightless conditions. In this paper, testing for the purpose of evaluating the effectiveness of Zero-G simulation using neutral buoyancy, conducted first of all in Japan, and recommendations on the equipment and Facilities required to conduct such simulations, are described.
Technical Paper

Space Station Freedom Distributed Systems-An Overview

1989-07-01
891524
The primary subsystems on Space Station Freedom are referred to as distributed systems. These systems include structures and mechanisms, electrical power, data management, internal audio/video, thermal control, man-systems, and the environmental control and life support systems. This paper describes the architectural layout of Work Package One {WP01) distributed systems within the Habitation and U.S. Laboratory modules and provides a brief description of each of these systems. Emphasis is placed on the environmental control and life support systems and the test plan to qualify these systems for flight.
Technical Paper

The Thermal Control of TDF-1- the First Six Months in Orbit

1989-07-01
891523
The direct broadcasting television satellite TDF-1 has been launched on October 28th, 1988, by ARIANE flight V 26 from KOUROU, French Guyana. After the successful on orbit tests, the five television channels have been activated on the 15th of November. One of the key features of this satellite consists in the sophisticated design of the heat pipe network used for the thermal control of the telecommunication payload. This network is composed of 86 constant conductance heat pipes of different diameters, corresponding to a total cumulative length of about 120 meters, and arranged along the three axes of the spacecraft body. The paper describes the thermal control design of this satellite and summarizes the development plan selected in connection with the constraints linked with the heat pipe utilisation. The second part is an overview of the in-orbit performance of the thermal control system during the first Month of operational utilisation.
Technical Paper

Air Loop Concepts for Environmental Control and Life Support

1989-07-01
891537
Air loops play a key role in the Environmental Control and Life Support Subsystems (ECLSS) of manned spacecraft. They constitute the essential interface between the crew and those ECLSS assemblies which are responsible for crew safety, comfort and health. Further, air is required to cool avionics and other equipment of the vehicle during the relevant operational phases. Thereby, air loops establish the essential interface between the ECLSS and the Thermal Control Subsystem (TCS). The paper gives a classification of air loops features of laboratory modules and discusses the design implementation aspects of the various conceptual approaches. Features addressed are centralised - decentralised ECLSS, separated - combined air loops, subfloor architecture, cabin loop ventilation and rack cooling. Particular emphasis is laid on the presently envisaged design solutions of the COLUMBUS programme elements.
Technical Paper

Crew System Dynamics: Combining Humans and Automation

1989-07-01
891530
With the advent of Space Station Freedom, manned spaceflight will begin to rely heavily on automated or “intelligent” systems. During the last few years there has been a growing realization that the effective use of automated systems requires careful attention to how well these systems mesh with, support, and are supported by, users. This paper considers some of the human factors issues involved in effectively combining human and automated systems. The possibilities and potential problems attendant to the use of automated systems are discussed as are the unique capabilities and possible errors introduced by human participants. Because of the total environment of space and the close coupling of humans and machines in the space environment, it is necessary to look beyond the individual user and to view human/automation interactions from the perspective of the total system, i.e. from the perspective of crew system dynamics.
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