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The design optimization of thin-walled tubular structures is of relevance in the automotive industry due to their low cost, ease of manufacturing and installation, and high-energy absorption efficiency. This study presents a methodology to design thin-walled tubular structures for crashworthiness applications. During an impact, thin-walled tubular structures may exhibit progressive collapse/buckling, global collapse/buckling, or mixed collapse/buckling. From a crashworthiness standpoint, the most desirable collapse mode is progressive collapse due to its high-energy absorption efficiency, stable deformation, and low peak crush force (PCF). In the automotive industry, thin-walled components have complex structural geometries. These complexities and the several loading conditions present in a crash reduce the possibility of progressive collapse. The Hybrid Cellular Automata (HCA) method has shown to be an efficient continuum-based approach in crashworthiness design.

Notched spoilers may be used to suppress flow-induced cavity resonance in vehicles with open sunroofs or side windows. The notches are believed to generate streamwise vortices that break down the structure of the leading edge cross-stream vortices predominantly responsible for the cavity excitation. The objectives of the present study were to gain a better understanding of the buffeting suppression mechanisms associated with notched spoilers, and to gather data for computational model verification. To this end, experiments were performed to characterize the surface pressure field downstream of straight and notched spoilers mounted on a rigid wall to observe the effects of the notches on the static and dynamic wall pressure. Detailed flow velocity measurements were made using hot-wire anemometry. The results indicated that the presence of notches on the spoiler reduces drag, and thus tends to move the flow reattachment location closer to the spoiler.

Complete reuse of graywater will be essential during long duration human space missions. The highest loaded and most important component to remove from graywater is surfactant, the active ingredient in soaps and detergents. When considering a biological treatment system for processing of graywater, surfactant biodegradability becomes a very important consideration. Surfactants should be chosen that are degraded at a fast rate and yield inconsequential degradation byproducts. Experiments conducted for this research examined the biodegradation of the surfactants in Pert Plus for Kids, disodium cocoamphodiacetate (DSCADA) and sodium laureth-3 sulfate (SLES), using respirometry. Rates of CO2 production, or ultimate degradation, are reported. DSCADA was found to be toxic to bacteria when present at 270 ppm whereas no toxicity was observed during experiments with SLES.

Numerical computations of combusting transient jets are performed under diesel-like conditions. Discussions of the structure of such jets are presented from global and detailed points of view. From a global point of view, we show that the computed flame heights agree with deductions from theory and that integrated soot mass and heat release rates are consistent with expected trends. We present results of several paramaters which characterise the details of the jet structure. These are fuel mass fractions, temperature, heat release rates, soot and NO. Some of these parameters are compared with the structure of a combusting diesel spray as deduced from measurements and reported in the literature. The heat release rate contours show that the region of chemical reactions is confined to a thin sheet as expected for a diffusion flame. The soot contour plots appear to agree qualitatively with the experimental observations.

The vertical force generated from terrain-tire interaction has long been of interest for vehicle dynamic simulations and chassis development. To improve simulation efficiency while still providing reliable load prediction, a terrain pre-filtering technique using a constraint mode tire model is developed. The wheel is assumed to convey one quarter of the vehicle load constantly. At each location along the tire's path, the wheel center height is adjusted until the spindle load reaches the pre-designated load. The resultant vertical trajectory of the wheel center can be used as an equivalent terrain profile input to a simplified tire model. During iterative simulations, the filtered terrain profile, coupled with a simple point follower tire model is used to predict the spindle force. The same vehicle dynamic simulation system coupled with constraint mode tire model is built to generate reference forces.

This paper explores the current status of error management strategies and human factors efforts within regional airlines. It briefly addresses the potential needs of the environment from a perspective of the market’s accident and incident history as well as anecdotal reports received from members of the regional airline community. It also raises questions concerning the applicability of human factors and error management strategies developed in other segments of aviation to the problems faced within regional airline environments.

AN INTERDISCIPLINARY TEAM from Purdue University is developing a comprehensive set of educational materials for agricultural safety and health for OSHA, of the U. S. Department of Labor. The team from the Purdue school of Agriculture, school of Veterinary Medicine, and the school of Humanities, Social Science and Education are working for a year and a half to gather and catalog all existing safety materials, and to produce new ones to meet nationwide needs. The project was begun on July 1, 1974 and is scheduled to be completed by December 31, 1975. The project team includes John B. Liljedahl, professor of agricultural engineering, project leader; Avery H. Gray, assistant department head, 4-H and Youth; William H. Hamilton, agricultural education; David H. Loewer, Extension agricultural engineer; David L. Matthew, Extension Entomologist; Vernon B. Mayrose, Extension animal scientist; Ken Weinland, Extension veterinarian; Bruce A. McKenzie, Extension agricultural engineer; James L.

Resource recovery, including that of urine water extraction, is one of the most crucial aspects of long-term life support in interplanetary space travel. This paper will consequently examine an innovative approach to processing raw, undiluted urine based on low-temperature freezing. This strategy is uniquely different from NASA's current emphasis on either ‘integrated’ (co-treatment of mixed urine, grey, and condensate waters) or ‘high-temperature’ (i.e., VCD [vapor compression distillation] or VPCAR [vapor phase catalytic ammonia removal]) processing strategies, whereby this liquid freeze-thaw (LiFT) procedure would avoid both chemical and microbial cross-contamination concerns while at the same time securing highly desirable reductions in likely ESM levels.

This paper provides a comparison of wall heat fluxes and quenching distances as one-dimensional hydrogen and heptane flames impinge head-on onto a wall. It is shown that the quenching distances for stoichiometric H2/air and C7H16/air flames under the specified conditions of this study are about the same, but the wall heat flux for the H2/air flames is approximately a factor of two greater. For lean H2/air mixtures, the quenching distance increases substantially and the wall heat flux decreases. To understand more clearly the interplay of flame speed, temperature, thermal diffusivity, and surface kinetics on the results, studies of H2/O2 flames are also carried out.

An important function of life support systems developed for a long duration human mission to Mars is the ability to recycle water and air. The Bio-Regenerative Environmental Air Treatment for Health (BREATHe) is part of a multicomponent life support system and will simultaneously treat wastewater and air. The BREATHe system will consist of packed bed biofilm reactors. Model waste streams will be used for experiments conducted during the design phase of the BREATHe system. This paper summarizes expected characteristics of water and air waste steams that would be generated by a crew of six during a human mission to Mars. In addition to waste air and water generation rates, the chemical composition of each waste stream is defined. Specifically, chemical constituents expected to be present in hygiene wastewater, dishwater, laundry water, atmospheric condensate, and cabin air are presented.

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.