published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

A graphic design campaign that aims to contribute to a positive attitude regarding mental illness. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Digitized by Kansas Correctional Industries

Typescript, etc. / Digitized by Kansas State University Libraries

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Common Airborne Instrumentation System (CAIS) is being developed by the Department of Defense through a Tri-service Program Office. The goals of the program are two fold. The first is to develop an instrumentation system that will meet the needs of the Air Force, Army, and Navy into the next century. The system is designed to support a full breadth of applications from a few parameters to engineering and management and development programs. The second is to provide a system that is airframe as well as activity independent. To accomplish these goals, the CAIS consists of two segments. The airborne segment consists of a system controller with a suite of data acquisition units. The system is configured with only the units that are required. The ground segment consists of a variety of support equipment. The support equipment enables the user to generate formats, load/verify airborne units, perform system level diagnostics and more.

The work presented in this thesis investigates design, computer modelling and testing a sub-wet bulb temperature evaporative cooling system for space air conditioning in buildings. The context of this evaporative cooling technology design is specifically targeted at locations with a hot and dry climate such as that prevailing in most regions of Middle East countries. The focus of this technology is to address the ever-escalating energy consumption in buildings for space cooling using mechanical vapour compression air conditioning systems. In this work, two evaporative cooling configurations both based on sub-wet bulb temperature principle have been studied. Furthermore, in these designs, it was sought to adopt porous ceramic materials as wet media for the evaporative cooler and as building element and use of heat pipes as heat transfer devices. In the first test rig, the prototype system uses porous ceramic materials as part of a functioning building wall element. Experimental and modelling results were obtained for ambient inlet air dry bulb temperature of 30 and 35oC, relative humidity ranging from 35% to 55% and intake air velocity less than 2 (m/s). It was found that the design achieved sub-wet bulb air temperature conditions and a maximum cooling capacity approaching 242 W/m2 of exposed ceramic material wet surface area. The wet bulb effectiveness of the system was higher than unity. The second design exploits the high thermal conductivity of heat pipes to be integrated as an effective heat transfer device with wet porous ceramic flat panels for evaporative cooling. The thermal performance of the prototype was presented and the computer model was validated using laboratory tests at temperatures of 30 and 35oC and relative humidity ranging from 35% to 55%. It was found that at airflow rates of 0.0031kg/s, inlet dry-bulb temperature of 35oC and relative humidity of 35%, the supply air could be cooled to below the inlet air wet bulb temperature and achieve a maximum cooling capacity of about 206 W/m2 of wet ceramic surface area. It was shown that the computer model and experimental tests are largely in good agreement. Finally, a brief case study on direct evaporative cooling thermal performance and environmental impact was conducted as part of a field trip study conducted on an existing large scale installation in Mina Valley, Saudi Arabia. It was found that the evaporative cooling systems used for space cooling in pilgrims’ accommodations and in train stations could reduce energy consumption by as much as 75% and cut carbon dioxide emission by 78% compared to traditional vapour compression systems. This demonstrates strongly that in a region with a hot and dry climate such as Mina Valley, evaporative cooling systems can be an environmentally friendly and energy-efficient cooling system compared to conventional vapour compression systems.

This thesis describes the work undertaken over a 3 year period under a Department of the Environment, Transport and the Regions (DETR) Partners in Technology programme in collaboration with four industrial partners. The aim of the work was to investigate the two-phase flow heat transfer and fluid dynamic performance of the non-ozone depleting refrigerants and lubricating oil mixtures in a horizontal tube. A single tube test facility was designed and built to determine local heat transfer coefficients and overall pressure drop for evaporation and condensation. A circulating pump system pressurised through an accumulator charged with nitrogen was selected to enable accurate setting of the evaporation and condensation conditions. The system was validated using R22. Tests were undertaken for R404A, R407C, Isceon 59 with a Polyol-ester lubricating oil. The experimental data consist of two-phase local heat transfer coefficients and overall pressure drops inside a smooth copper tube. Numerous data were obtained for evaporation and condensation, and constituted a large database of two-phase heat transfer coefficients. The experimental results were compared with several existing correlations traditionally used in heat exchanger design, to assess their suitability with the new refrigerants. As a result of these comparisons offering a poor agreement, a model characterising the variation of the local heat transfer coefficient was developed. The evaporation model consists in a modification of the Kattan et al. model (1998a, b & c). The new model predicts the experimental results well, with a standard deviation of 6.1% for refrigerant R407C and Isceon 59. The effects of lubricating oils on two-phase flow heat transfer are also discussed qualitatively. This work provides a design tool when dealing with the non-ozone depleting refrigerants, and recommendations are made on the use of several correlations.

International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California / This paper describes the changes in signal conditioning techniques used on flight test programs in recent years. Improved sensors require improved signal conditioning. Advanced distributed data acquisition systems, used on major flight test programs, move the signal conditioning closer to the sensor for improved performance and reduced wiring throughout the vehicle. These distributed systems use digital communication between the master controller and the remote conditioning units for improved accuracy and noise immunity. This requires sample- and-hold amplifiers, analog-to-digital converters, and serial encoder/decoders to be located at the signal conditioning location. The changes in signal conditioning designs are driven by the sensors, the architecture of the data acquisition systems, and by vehicle designs (smaller aircraft, smaller missiles, composite structures, and hypervelocity vehicles). A look at the signal conditioning technology employed in many of these systems as well as what is anticipated in the future is described in this paper.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Caterpillar Inc. has been testing construction and mining equipment using Computerized Analysis Vans for two decades. During our latest van upgrade, we chose to move to PCM/FM from FM/FM mainly to increase the channel count. We also replaced our old signal conditioning that used span and balance potentiometers with computer programmable signal conditioning. This new signal conditioning requires that the gain and balance point be calculated for every channel on each test. The formulas for these calculations depend on the sensor, the signal conditioning card used, and the test requirements. Due to the number and variety of machines tested at the Caterpillar Proving Grounds, these calculations needed to be automated. Using a few initial parameters and the information from our sensor calibration database, each channel’s balance point, gain, and expected slope are calculated. This system has increased productivity, accuracy, and consistency over manually calculating these parameters. This paper covers the sensor database, the calculated parameters and an overview of the way the system works.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / NASA and Lockheed Martin Telemetry & Instrumentation have jointly developed a new data acquisition system for the Space Shuttle program. The system incorporates new technologies which will greatly reduce manpower requirements by automating many of the functions necessary to prepare the data acquisition system for each shuttle launch. This new system, the Automated Data Acquisition System (ADAS), is capable of configuring itself for each measurement without operator intervention. The key components of the ADAS are the Universal Signal Conditioning Amplifier (USCA), the Transducer Electronic Data Sheet (TEDS), and the Data Acquisition System (DAS 450). The ADAS is currently being delivered and installed at Kennedy Space Center. NASA and Telemetry & Instrumentation are actively pursuing commercialization of the ADAS and its associated products which will be available during 1996.