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Technical Paper

“Condensation – Why it Needs to be Addressed in Every Aircraft”

A wide body aircraft carries almost a half–ton of water and ice between the cabin and skin of the aircraft. The water can get on wires and connectors, which can cause electrical problems, cause corrosion and rust, and, eventually, “rain in the plane”. The speaker is the CEO of CTT Systems that has developed a system that solves the condensation by using dry air. The speaker will discuss how condensation can be prevented and how airlines can also save maintenance costs in the process. This topic is relevant for the attendees at the Aerospace Expo, as they are decision makers who need to be aware of this issue. It is also important for the MRO shows as the attendees are on the front lines of dealing with this problem.
Technical Paper

“A Dry Aircraft is a Safer Aircraft – Beating Condensation by Using Dry Air”

The airline industry seems to be providing more leisure features on planes like inflight entertainment, Internet access and Digital TV, but it seems the airline industry has ignored the issue of excess condensation on aircraft, which had plagued carriers since the birth of the airline industry. How safe are passengers when a wide body aircraft carries in excess almost a half ton of water and ice between the cabin and skin of the aircraft? Besides the added weight straining the aircraft, excess condensation soaks wires and connectors which can cause electrical shorts. There have been instances of emergency doors frozen shut, locked by ice stemming from excess water dripping inside the plane. Extra water also causes “rain-in-the-plane”, an issue that has gained national attention and causes passenger discomfort. It's time for the industry to address what has become a serious issue.
Technical Paper

‘Bigelow Aerospace® Life Support Laboratory - Planning and Status’

This Life Support Laboratory consists of a simulator of the spacecraft called Nautilus, which houses Air Revitalization Subsystem, Atmospheric Control and Supply, and Fire Detection and Suppression in the Equipment Area. There are supporting facilities including a Human Metabolic Simulator, simulated Low and Moderate Temperature Coolant Loop, chemical analysis bench, purified water supply, vacuum and gas supplies. These facilities are scheduled to be completed and start to operate for demonstration purposes by March 2005. There are an ARES Ground Model (AGM) and a Trace Contaminant Control Assembly in the ARS. The latter will be integrated with the AGM and a Condensing Heat Exchanger. The unit of AGM is being engineered, built, and will be delivered in early 2005 by EADS Space Division. These assemblies will be operated for sensitivity analysis, integration and optimization studies. The main goal is the achievement for optimal recovery of oxygen.
Technical Paper

srv-k Status Aboard the International Space Station During Missions 15 and 16

The paper summarizes the experience gained on the ISS water management system during the missions of ISS-1 through ISS-16 (since November 2 2000, through December 31, 2007). The water supply sources and structure, consumption and supply balance at various phases of space station operation are reviewed. The performance data of the system for water recovery from humidity condensate SRV-K and urine feed and pretreatment system SPK-U in the Russian orbital segment are presented. The key role of water recovery on a board the ISS and the need to supplement the station's water supply hardware with a system for water reclamation from urine, water from a carbon dioxide reduction system and hygiene water is shown.
Technical Paper

Zero-Venting, Regenerable, Lightweight Heat Rejection for EVA Suits

Future space exploration missions will require a lightweight spacesuit that expends no consumables. This paper describes the design and performance of a prototype heat rejection system that weighs less than current systems and vents zero water. The system uses regenerable LiCl/water absorption cooling. Absorption cooling boosts the heat absorbed from the crew member to a high temperature for rejection to space from a compact, non-venting radiator. The system is regenerated by heating to 100°C for two hours. The system provides refrigeration at 17°C and rejects heat at temperatures greater than 50°C. The overall cooling capacity is over 100 W-hr/kg.
Technical Paper

Zero-G Water Selection Separator: A Performance Tradeoff

This paper presents a trade-off study to select a water separator system for a 3-man, 140-day, zero-g mission. Included is a summary of feasible concepts, a compilation of data on existing hardware, and a comparison of the performance characteristics of each with respect to the overall system. Six approaches to zero-g water separation were considered and are discussed: hydrophobic/hydrophilic screens; integrated condenser-water separators; centrifugal separators; cellular sponges; vortex separators; and elbow separators. Some of these techniques have high-performance characteristics with regard to water removal efficiency. However, when reduced to hardware, these same techniques may not integrate well with the overall system. The system selected was the integrated condenser-water-separator. This system requires no power, has no moving parts, and has a very small envelope.
Technical Paper

Zero Gravity Phase Separator Technologies - Past, Present and Future

Spacecraft life support equipment is often challenged with two phase flow, where liquid and gas exist together. In the zero gravity environment of an orbiting spacecraft, the behavior of a liquid/gas interface is dominated by forces not usually observed in one “G” due to the overwhelming effects of gravity. The normal perceptions no longer apply. Water does not run down hill and bubbles do not rise to the surface. Surface energy, capillary forces, wetting characteristics and momentum effects predominate. Techniques and equipment have been developed to separate the liquid/gas mixture into its constituent parts with various levels of efficiency and power consumption.
Technical Paper


This paper investigates the use of several zero-ozone depleting potential (zero-ODP) HFC refrigerants, including HFC-134a, HFC-227ca, HFC-227ea, HFC-236ea, HFC-236cb, HFC-236fa, HFC-245cb, and HFC-254cb, for centrifugal chiller applications. We took into account the thermodynamic properties of the refrigerant and aerodynamic characteristics of the impeller compression process in this evaluation.. For a given operating temperature lift, there are significant differences in the pressure ratio required by each refrigerant and this variation in pressure ratio directly affects compressor size, efficiency, and performance. A comparison of the HFC refrigerant candidates with CFC-114 shows that HFC-236ea, HFC-227ca and HFC-227ea are viable alternatives for centrifugal water chillers. HFC-236ea has properties closest to CFC-114, and will result in comparible performance, but will require a slightly larger impeller and a purge system.
Technical Paper

X-Ray - A Necessary Tool for Detecting Incipient Structural Failures in Service Aircraft

X-ray is an indispensable aid in locating and determining the extent of incipient failures in structure which is inaccessible by position or covered by multiple layers of metal. It is also the most feasible method for checking oil coolers for contamination; bonded honeycomb panels for water; fuel lines for erosion; and with a 360 deg emission tube, fuselage frames for structural integrity without removing the interior upholstery and panels from the passenger compartment or cargo compartments.
Technical Paper

Wissler Simulations of a Liquid Cooled and Ventilation Garment (LCVG) for Extravehicular Activity (EVA)

In order to provide effective cooling for astronauts during extravehicular activities (EVAs), a liquid cooling and ventilation garment (LCVG) is used to remove heat by a series of tubes through which cooling water is circulated. To better predict the effectiveness of the LCVG and determine possible modifications to improve performance, computer simulations dealing with the interaction of the cooling garment with the human body have been run using the Wissler Human Thermal Model. Simulations have been conducted to predict the heat removal rate for various liquid cooled garment configurations. The current LCVG uses 48 cooling tubes woven into a fabric with cooling water flowing through the tubes. The purpose of the current project is to decrease the overall weight of the LCVG system. In order to achieve this weight reduction, advances in the garment heat removal rates need to be obtained.
Technical Paper

Water-Vapor Electrolysis Cell with Phosphoric Acid Electrolyte

An oxygen-producing water electrolysis cell with phosphoric acid electrolyte can operate on the water vapor in recirculated cabin air and accomplish concurrent dehumidification. The development of the concept over the past 3 years involved research to define the components of electrode overvoltage and design analysis to provide a small, lightweight unit to compensate for the electrolysis power. Theoretical equations based on electrochemistry, fluid dynamics, and heat and mass transfer correlate with the observed steady state operation obtained in extended testing of experimental cells for over 1000 hr. Data on electrode life, gas purity, and voltage characteristics combined with size, weight, and power estimates indicate that the new concept would be competitive with other methods of oxygen generation for advanced space missions. The recent satisfactory performance of a prototype module in an extended test of over 1000 hr is reviewed.
Technical Paper

Water for Two Worlds: Designing Terrestrial Applications for Exploration-Class Sanitation Systems

At the United Nations Millennium Summit in September of 2000, the world leaders agreed on an ambitious agenda for reducing poverty and improving lives: the Millennium Development Goals (MDGs)1, a list of issues they consider highly pernicious, threatening to human welfare and, thereby, to global security and prosperity. Among the eight goals are included fundamental human needs such as the eradication of extreme poverty and hunger, the promotion of gender equality, the reduction of child mortality and improvement of maternal health, and ensuring the sustainability of our shared environment. In order to help focus the efforts to meet these goals, the United Nations (UN) has established a set of eighteen concrete targets, each with an associated schedule.
Technical Paper

Water and Energy Transport for Crops under Different Lighting Conditions

When high-intensity discharge (HID) electric lamps are used for plant growth, system inefficiencies occur due to an inability to effectively target light to all photosynthetic tissues of a growing crop stand, especially when it is closed with respect to light penetration. To maintain acceptable crop productivity, light levels typically are increased thus increasing heat loads on the plants. Evapotranspiration (ET) or transparent thermal barrier systems are subsequently required to maintain thermal balance, and power-intensive condensers are used to recover the evaporated water for reuse in closed systems. By accurately targeting light to plant tissues, electric lamps can be operated at lower power settings and produce less heat. With lower power and heat loads, less energy is used for plant growth, and possibly less water is evapotranspired. By combining these effects, a considerable energy savings is possible.
Technical Paper

Water Vapor Recovery from Plant Growth Chambers

NASA is investigating the use of plant growth chambers (PGCs) for space missions and for bases on the moon and Mars. Key to successful development of PGCs is a system to recover and reuse the water vapor that is transpired from the leaves of the plants. In this paper a design is presented for a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in PGCs. The system is based on two membrane technologies: 1) dehumidification membrane modules to remove water vapor from the air, and 2) membrane contactors to return water vapor to the PGC (and, in doing so, to control the humidity and temperature within the PGC). The membrane-based system promises to provide an ideal, stable growth environment for a variety of plants, through a design that minimizes energy usage, volume, and mass, while maximizing simplicity and reliability.
Technical Paper

Water Vapor Pollution of the Upper Atmosphere by Aircraft

The two combustion products which future technology will be unable to eliminate from present day jet engines are carbon dioxide and water vapor. The potential climatic change effects of carbon dioxide are considered to be a small part of a larger CO2 problem. Water vapor added to the troposphere forms contrails. The paper will assess the non-conclusive evidence of increased cirrus cloudiness at certain locations. Finally the potential climatic effects of added water vapor in the stratosphere on the radiation budget, the small decrease in ozone, and polar night cloudiness is evaluated in the light of future commercial aviation injections of water vapor.
Technical Paper

Water Supply Based on Water Reclamation from Humidity Condensate and Urine on a Space Station

The paper reviews an integrated system for space station water supply based on a combination of water recovery systems and a water resupply system. The water balance data and system performance data in long-duration operation on the Mir space station are presented. A water supply concept for the Russian's segment (RS) of the International Space Station (ISS) is substantiated.
Technical Paper

Water Supply Assembly for Hermes ECLSS

The Water Supply Assembly (WSA) is part of the Liquid Management Section (LMS) of the Hermes Environmental Control and Life Support Subsystem (ECLSS) (see ref. [1] and [2]). The WSA has to provide pure water for drinking and food preparation (rehydratation of dry food and beverage powder) and to provide pure water for hygiene purposes (oral hygiene and towel wetting). To obtain different desired temperatures (as well as different quantities of water to be dispensed), a heating device, using electrical foils, and a cooling device, using a water/water heat exchanger have been designed with regard to the critical mass and power requirements. Two dispensers are used to fill food/beverage or hygiene (towels) containers. As part of the Hermes C1 phase, breadboard models of the heating device (heater) and of the cooling device (chiller) have been manufactured and functionally tested.

Water Spray and High Humidity Endurance Test Methods for SAE Ams 1424 and SAE Ams 1428 Aircraft Deicing/Anti-Icing Fluids

This document establishes the minimum requirements for an environmental test chamber, and test procedures to carry out anti-icing performance tests according to the current materials specification for aircraft deicing/anti-icing fluids. The primary purpose for such a test method is to determine the anti-icing endurance under controlled laboratory conditions of AMS 1424 Type I and AMS 1428 Type II, III and IV.

Water Solution Type Hand Fire Extinguisher

.This specification covers the following types and classes of extinguishers: Type I Stored pressure type, Category A - Temperature range -40 to +140, Category B - Temperature range +35 to +140. Type II Cartridge operated type, Category A - Temperature range -40 to +140, Category B - Temperature range +35 to +140. To specify minimum requirements for a water solution type hand fire extinguisher which shall be suitable for use on incipient fires which may occur in an airplane cabin interior. The type of fire for which these units are intended is one involving combustible materials such as paper, textiles and similar materials
Technical Paper

Water Solubility in Different Alternative Jet Fuels: A Comparison with Petroleum-Based Jet Fuel

The paper presents an extensive assessment of the hygroscopic characteristics of a number of alternative jet fuel blends. These are blended with conventional Jet A-1 to conform with current aviation standards at a 50:50 ratio by volume, except for DSHC (Direct Sugar to Hydrocarbon), which is blended at 10% DSHC and 90% Jet A-1. Given the lack of information available on the water solubility of alternative jet fuels, an effective analysis of experimental data about this characteristic in six different alternatives was performed. These included four ASTM approved alternatives (two Fischer-Tropsch (FT) synthetics from coal and natural gas, one HEFA (Hydroprocessed Esters and Fatty Acids) derived from camelina and DSHC. An extra two alternatives currently under consideration for ASTM approval were also tested; ReadiJet and an ATJ (Alcohol to Jet).