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A connectable/disconectable thermal interface has been developed for the constructable radiator system under development at NASA-Johnson Space Center. A contact heat exchanger approach which involves pressurized clamping of a segmented cylindrical heat exchanger on the outside of a round heat pipe evaporator section was designed, fabricated, and tested. Dry metal-to-metal contact conductance heat transfer is utilized. Test results have indicated excellent contact conductances of up to 8500 w/m2°c (1500 Btu/ft2°F) at 2000 kPa (300 psi) clamping force. The feasibility and fabricability of the design have been demonstrated.

An automated nutrient replenishment system has been developed in order to provide a constant electrical conductivity (EC) value for the nutrient solution over the period of plant growth. A single nutrient film technique (NFT) system developed by the Tuskegee University NASA Center was equipped with the EC control system for growth trials with sweetpotatoes. The system is completely controlled and monitored by a PC through the use of LabView instrumentation and data acquisition software. A submersible EC probe driven by an EC controller measures the EC of the nutrient solution reservoir. EC values are passed from the controller to the PC through analog outputs. If the EC is outside a given range, the PC sends a signal to one of two solenoid valves that allow concentrated stock solution or deionized water to enter the reservoir to either raise or lower the EC respectively. For this application the set point is 1200μS cm-1, with a dead band from 1180 to 1220μS cm-1.

The system that will be presented consists of a Crawling Portable Robot (CPR) for drilling large air frame components as a part of the whole assembly process of fuselage or wing type sub-structures. Currently, the drilling of such components is massively fulfilled manually in a very labour intensive and “craft-based” manner. The operations are conducted in cramped, dangerous conditions and often involve unhealthy postures. The alternative to this situation consists in the use of large fixed-base multi-axis machines mounted upon a foundation on the shop floor. These machines are quite expensive, and also have a number of operational limitations. Because of their large working envelope, it is difficult for these machines to hold close tolerances over the entire range of all movement axes of the machine. Hence, there is a need to probe and calibrate the machine to the workpiece one or more times during work operations with the consequent negative impact in productivity.

Paper describes analysis of the design process of modern automotive LPG and CNG containers. Over decade experience in the field of both computer based analysis as well as in the real conditions testing has been collected and presented in the paper. Authors present the potentials of modern FEM methodologies in the optimization and production of lightweight steel containers. It has been proved that the most sophisticated numerical analysis have to be followed by the construction verification, particularly considering direct exposure to fire. Bonfire test have become obligatory for both liquid and compressed gases containers. Properly chosen fire protection system, together with the adequate level of quality of materials applied for its production together with proper directing of the gas flowing out from safety devices are the essential factors defining gas containers fire safety.

This paper is a discussion of the relative merits of the front, mid and rear engined car concepts. After discussing some basic packaging considerations, and implications in respect of legislation, the authors make comparisons of performance potential in respect of traction and aerodynamics. Limiting power weight ratios are derived. Primary and secondary ride implications are reviewed and effects on braking are mentioned. Steering and cornering characteristics are assessed by first establishing correlation between prediction and measurement using actual vehicles. Means of simplifying the prediction of steady state steering characteristics are described. Two “model” cars of front and mid engined configuration are then used to predict the steady state and dynamic steering consequences of various specification changes and some conclusions are drawn as to inherent differences.

The increasing use of embedded electronics in aerospace and automotive vehicles increases the designers' concern regarding the reliability of the components as well as the reliability of their interconnections. The discussion about the most appropriate method for assessing the reliability of solder joints for a given application is an ever-present theme in the literature. Several methods of prediction have been developed for assessing the reliability of solder joints. The standard method established by the industries for assessing reliability of solder joints is the thermal cycling. However, when the thermal distributions in real applications are studied, particularly in some electronic components used in on-board electronics of space systems, the thermal cycling does not represent what actually happens in practice in the packaging.

This paper describes a new leveling system which addresses itself to the needs of future, lighter weight vehicles for which attitude control is more important and engine vacuum is partly or totally unavailable. The system utilizes reverse air flow to clean its filter and regenerate its air dryer for lifetime moisture control. The electronic controller and high capacity compressor provide positive response without the use of a storage tank. The reduced number of air fittings and an improved “snap-on” fitting help guard against leaks. This system is described as it interfaces with passenger cars and light trucks using air-adjustable springs in the suspension system.

A dynamic simulation model has been developed for a vapor-cycle cooling system designed for aircraft applications using the latest technology developments. The heat exchanger models use multiple-, lumped-parameter, fixed-length elements based on coupled thermal and mass storage effects, and flow equations that incorporate the effects of thermal expansion and contraction. This model is developed to include the two-phase constant pressure temperature gradient unique to refrigerant mixtures. The full system model incorporates global mass conservation which is essential for accurate pressure levels and, thus, dynamic response and steady state performance. Phase boundary-based coordinate transformations on the nonazeotropic refrigerant mixture property data result in improved accuracy and computation efficiency. The simulation is developed with modular components with causality defined to minimize connection states and thus execution time.

The introduction of drive-by-wire systems into modern vehicles has generated new challenges for the designers of embedded systems. These systems, based primarily on microcontrollers, need to achieve very high levels of reliability and availability, but also have to satisfy the strict cost and packaging constraints of the automotive industry. Advances in VLSI technology have allowed the development of single-chip systems, but have also increased the rate of intermittent and transient faults that come as a result of the continuous shrinkage of the CMOS process feature size. This paper presents a low-cost, fault-tolerant system-on-chip architecture suitable for drive-by-wire and other safety-related applications, based on a triple-modular-redundancy configuration at the processor execution pipeline level.

This paper describes the joint effort between Ford Motor Company, Special Vehicle Operations (SVO), and Roush Industries to investigate the feasibility of making a production Ford 4.6L 4-Valve Modular V8 Engine into a 600 BHP road racing engine. All areas of the production engine design were addressed due to the anticipated increase in power and engine speed. No attempt was made to obtain race level durability or specific vehicle packaging. The test results showed that the objective power level was achieved at lower than anticipated engine speed. In addition, the torque values and band width were consistent with current road racing engine performance levels. In summary, the Ford 4.6L 4-Valve Modular V8 Engine can be developed into a competitive road racing engine. See FIGURE A.

The BSTCA (Battery Section Thermal Control Assembly) is a module of the Columbus MTFF (Man Tended Free Flyer). Electrical power required during eclipse periods, is made available from six nickel hydrogen batteries. A sophisticated multi-radiator configuration, with a hybrid heat pipe network, has evolved. Autonomous control of the assembly heat rejection capability has been achieved by a integrated network of LTHP's (Liquid Trap Heat Pipes) and CCHP's (Constant Conductance Heat Pipes) under the control of a conventional HCU (Heater Control Unit). The process of design selection and verification is discussed, for the BSTCA, with a detailed LTHP component presentation.

There are several reasons why it can be daunting to apply Six Sigma to product creation. Foremost among them, the functional performance of new technologies is unknown prior to starting a project. Although, Design For Six Sigma (DFSS) was developed to overcome this difficulty, a lack of applicable in-class case studies makes it challenging to train the product creation community. The current paper describes an in-class project which illustrates how Six Sigma is applied to a simulated product creation environment. A toy construction set (TCS) project is used to instruct students how to meet customer expectations without violating cost, packaging volume and design-complexity constraints.

Rotary position sensors (RPS) currently are applied widely in engine management systems for throttle position sensing and are being considered for other applications such as drive-by-wire. The potentiometer RPS relies on contact between a resistive element and a wiper and thus has an inherent wear mechanism. This paper describes a noncontacting RPS which is essentially a drop-in replacement for the present device. A linear output Hall Effect IC is key to achieving the required functionality, but it must be combined with a magnetic actuation scheme which provides a very linear and stable magnetic field as a function of input angle and packaging which provides long life and control of mechanical tolerances. Each of these design elements will be discussed.

This work presents the results of an experimental High Performance Miniature Loop Heat Pipe. The evaporator utilizes a wick structure with the non-inverted meniscus evaporation concept, which allows using high thermal conductivity materials for the evaporator case and capillary wick structure, and hence will further reduce the thermal resistance between the evaporator elements. The heat fluxes at the evaporator can therefore be significantly higher than that of a LHP using inverted meniscus evaporation approach. Tests were conducted in the Material and Thermal Laboratory at the Canadian Space Agency. The evaporator heat input cross-section area was 2.4 cm2. When water is used as the working liquid the heat transfer rate has reached values as high as 215W, corresponding to a heat flux density of 90W/cm2 (temperature drop between heat source and LHP evaporator was ∼7°C). Working temperature oscillations (with amplitude ∼2-10°C) were observed for steady state regimes of LHP operation.

A high pressure and high temperature evaporation model was implemented in the KIVA-3 multidimensional engine simulation. The most significant features of the new evaporation model are: the effects of Stefan flow on transfer rates are included; internal circulation is accounted using the effective conductivity model of Abramzon and Sirignano [1]; equilibrium composition is calculated at high pressures using a real gas equation of state; and properties are evaluated as functions of temperature, pressure and composition. The evaporation of a continuous spray of n-dodecane injected in a chamber pressurized with nitrogen gas was simulated using the two models. Predictions of the evaporation rate, the spray penetration and fuel vapor distribution by the two models were significantly different. The differences persisted over a range of ambient pressures and temperatures, injection velocities, initial droplet sizes and fuel volatilities.

The evolution of farm tractors had its beginning at the turn of the century. The designs were limited by the preference of purchasers who made their buying decisions motivated by profit making ability. Each new generation of tractors included safety features, but these virtues were disguised and advertised as productivity improvements. Earthmoving and material handling machines came into existence after World War II to displace the practice of adapting farm tractors. A whole new industry was created to meet the demand for immense construction and logging machines. The purchasers of these machines were employers who made their buying decisions based upon a different perspective than the former buyer-user farm tractor buyers. Regulations and requirements pertaining to safety became a part of the logging and construction industries in the latter part of the 1960's. Regional producers came into being to provide safety devices that met these requirements.

Improved propulsion system cooling remains an important challenge in the transportation industry as heat generating components, embedded in ground vehicles, trend toward higher heat fluxes and power requirements. The further minimization of the thermal management system power consumption necessitates the integration of parallel heat rejection strategies to maintain prescribed temperature limits. When properly designed, the cooling solution will offer lower noise, weight, and total volume while improving system durability, reliability, and power efficiency. This study investigates the integration of high thermal conductivity (HTC) materials, carbon fibers, and heat pipes with conventional liquid cooling to create a hybrid “thermal bus” to move the thermal energy from the heat source(s) to the ambient surroundings. The innovative design can transfer heat between the separated heat source(s) and heat sink(s) without sensitivity to gravity.

Among the various alternative fuels, hydrogen is the only fuel, which is clean and sustainable. More importantly, if hydrogen is produced from renewable resources, virtually no CO2 emissions are produced. Texaco Ovonic Hydrogen Systems (TOHS) has converted a gasoline internal combustion engine (ICE) hybrid vehicle to a hydrogen vehicle using its advanced metal hydride storage. Compared to its gasoline counterpart, the converted vehicle demonstrated a reduction in CO2 tailpipe emission of 220 grams per mile. Ovonic metal hydride hydrogen storage systems consist of three critical elements: (1) an advanced metal hydride alloy, (2) an efficient heat exchanger and (3) a lightweight fiber wrapped pressure container. A 50 liter Ovonic metal hydride storage vessel installed in the vehicle provides a storage capacity of 3 kg hydrogen and a driving range of 130-150 miles.

With the so called “Energy Crisis” upon us, the cost and availability of plant lubricants have become of prime importance to management. Although the re-refining of waste oils is far from a new concept, it is just now being generally accepted as a means of reducing costs, while resolving liquid waste disposal problems and assuring a guaranteed source of supply.

Vehicle packaging is an important and portal phase during the vehicle design cycle. The design task of vehicle packaging can be considered as the process of packaging the main components in their appropriate positions, which should provide harmonious relationships with each other, and guarantee the vehicle's performance requirements in a specific environment. In the traditional design, from the initial conditions to a satisfactory result, it will take a long time even under the advanced CAD environment. Incorporating the state-of-the-art knowledge based engineering technology into the design process to provide rapid and optimal design abilities. The design system flow can be outlined as four steps as: specification, customization, assessment, and inference. The design system mechanism is a typical KBE running mechanism. Audi 100 model is used to verify this design system.