Search results

The purpose of this paper is to present the results of the preliminary design and optimization of the air-intake system and the engine nacelle. The work was conducted as part of an integration process of a turboprop engine in a small aircraft in a tractor configuration.

The preliminary design process was performed using a parametric, interactive design approach. The parametric model of the aircraft was developed using the PARADES™ in-house software. The model assumed a high level of freedom concerning shaping all the components of aircraft important from the point of view of the engine integration. Additionally, the software was used to control the fulfillment of design constraints and to analyze selected geometrical properties. Based on the developed parametric model, the preliminary design was conducted using the interactive design and optimization methodology. Several concepts of the engine integration were investigated in the process. All components of the aircraft propulsion system were designed simultaneously to ensure their compliance with each other.

The concepts of the engine integration were modified according to changes in the design and technological constraints in the preliminary design process. For the most promising configurations, computational fluid dynamics (CFD) computations were conducted using commercial Reynolds-averaged Navier–Stokes solver FLUENT™ (ANSYS). The simulations tested the flow around the nacelle and inside the air-delivery system which consists of the air-intake duct, the foreign-particles separator and the auxiliary ducts delivering air to the cooling and air-conditioning systems. The effect of the working propeller was modeled using the Virtual Blade Model implemented in the FLUENT code. The flow inside the air-intake system was analyzed from the point of view of minimization of pressure losses in the air-intake duct, the quality of air stream delivered to the engine compressor and the effectiveness of the foreign particles separator.

Based on results of the CFD analyses, the final concept of the turboprop engine integration has been chosen.

The presented results of preliminary design process are valuable to achieve the final goal in the ongoing project.

Reports on the implications for facilities managers attendant to selecting among various service distribution methods, in particular wire and air distribution methods. Details the performance capabilities of various distribution methods. Concludes that fully functional, efficient buildings are just as critical to financial performance as the salesforce, engineering or manufacturing.

THE Deutsche Luftfahrtschau, or as it is more generally known, the Hanover Air Show, is held every two years by the Bundesverband der Deutschen Luft‐ und Raumfahrtindustrie e.V. (Federal Association of the German Air and Spacecraft Industries). This year's Show will be held from April 29 to May 8 at the Hanover Langenhagen Airport and will be held at the same time as the Hanover Fair.

Interlending in Canada is affected by geographic, political and cultural factors. The population distribution complicates the provision of material services and new methods of document delivery are constantly under review. The political complexities are such as to make effective networking voluntary, informal or non‐governmental. A complex cultural background affects library collections and services. Interlending in Canada is vital as individual library collections are not yet fully developed. There are no central lending collections as such and interlibrary lending is largely decentralized. Location tools and services have changed radically over the last decade with the advent of automation. The introduction of air and truck delivery systems has solved many document delivery problems and they are developing rapidly. Interlibrary loan policies are based on a code which, amongst other things, promotes access to information as being in the general interest. Charges for interlibrary loans were reluctantly introduced in 1975 and caused temporary chaos. The issue has raised the question of the need for a national lending centre and this in turn raises the problem of copyright. A nationwide study of interlending in Canada was undertaken and the report submitted at the end of 1982. Other studies are being carried out at the provincial level. Interlending in Canada is in a very dynamic period: technology is moving towards the interlinking of a wide variety of systems better suited to the Canadian situation. In future, library collections may become smaller, and users will borrow from a central clearing‐house, or full‐text database. New technology will affect the traditional role of the library which will then concentrate on more sophisticated help to the user.

Chadderton, England — the home of British Aerospace PLC (BAe), the British company which plays an important role in the Airbus project as designer and builder of the wings for A300, A310, A320 and A340 aircraft. The wings are designed at BAe, Filton, prior to machining at Chadderton, following which assembly is undertaken at BAe in Chester. The company has a one‐fifth share in the Airbus business representing £1 billion turnover and with orders and deliveries for the aircraft approaching 900, the importance of Airbus to the plant is continuing to increase.

The case compares two U.S. Department of Defense (DoD) programs from the 1970s and 1980s: (1) “stealth” combat aircraft, capable of evading detection or engagement by anti-aircraft systems, and (2) precision attack of hardened ground vehicles from “standoff” distances, i.e., far behind the battle lines. Conceived at roughly the same time, motivated by the same strategic challenge, and initially driven by the same DoD organization, stealth combat aircraft progressed from idea to deployment in less than eight years---an astounding pace for a complex military system---while a demonstrated system for standoff precision strike against mobile ground targets was not fully implemented. The case highlights the critical role of the Defense Advanced Research Projects Agency (DARPA), part of the DoD, regarded as one of the most innovative entities in the U.S. federal government.

The case highlights factors that facilitate rapid, successful implementation of radically innovative or disruptive concepts. Students are introduced to the organizational realities facing such projects, including issues of strategic clarity, interdepartmental competition and cooperation, executive leadership, and timing. Comparing the differences in implementation of the two programs in the case reveals issues relevant to any large organization seeking to bring innovative concepts to fruition.

The purpose of this paper is to present results of practical experience of cold starting a gasoline engine on low volatility fuel suitable for unmanned aerial vehicle (UAV) deployment.

Experimental research and development is carried out via dynamometer testing of systems capable of achieving cold start of a spark ignition UAV engine on kerosene JET A-1 fuel.

Repeatable cold starts have been satisfactorily achieved at ambient temperatures of 5°C. The approximate threshold for warm engine restart has also been established.

For safety and supply logistical reasons, the elimination of the use of gasoline fuel offers major advantages not only for UAVs but also for other internal combustion engine-powered equipment to be operated in military theatres of operation. For gasoline crankcase-scavenged two-stroke cycle engines, this presents development challenges in terms of modification of the lubrication strategy, achieving acceptable performance characteristics and the ability to successfully secure repeatable engine cold start.

The majority of UAVs still operate on gasoline-based fuels. Successful modification to allow low volatility fuel operation would address single fuel policy objectives.

This paper aims to summarize researches conducted related to functional textiles for prevention of pressure ulcers and critical analysis of the outcomes to pave path for the future research in this area for benefit of the patients. Pressure ulcers, also known as bed sores, pressure sores and decubitus ulcers, are localized areas of tissue damage that develop due to pressure usually over a bony prominence. A standard hospital mattress has an interface pressure of 100 mmHg which can result in pressure ulcers unless repositioning occurs at regular intervals. Moisture accumulation on the skin is an important physical factor predisposing a patient to the occurrence of pressure ulcers and tissue breakdown. The disability leads to several requirements of functional clothing and textile products. The textiles play a variety of roles in this concern, from simply having good aesthetic appearance to preventing life threatening risks. An ideal support surface prevents pressure ulcers by providing pressure redistribution and maintaining a healthy skin microenvironment. The use of the textiles for the care of elderly disabled and bedridden persons can play an important role, as their quality of life can be improved by making use of functional and good-looking textiles.

This review paper aims to summarize researches conducted related to functional textiles for prevention of pressure ulcers and critical analysis of the outcomes to pave path for the future research in this area for benefit of the patients.

In the past years, there have been several functional textiles developed for the prevention of pressure ulcer. They are designed to maintain proper microclimate around patient skin. Sheepskin is one of the oldest used bed overlays which prevent pressure ulcer but its prolonged use leads to uneasy feeling for the patient. A sensor in bed for pressure detection is one of the good alternatives as it provides proper indication on when to change the position of the patient so that the pressure can be shifted and ulcers is prevented. These sensors are costly and complex to setup so for common man they are not easily available. Multilayer textiles on the other hand are complex to make as the properties are dependent upon the fiber content, yarn structure, fabric structure and technique of layering them together. Spacer fabric provides good air and moisture permeability, but there is a scope to study this type of fabric by varying the fibers type and thickness of the spacer fabric. A bedding material which is not much complex and can be easily purchased and used by common man for in-house usage is the need of the hour.

There is no comprehensive review available regarding research in this area with critical analysis of the outcomes for future study.

Bell Helicopter Textron announced it has received one of the largest orders for commercial helicopters in the company's history. Petroleum Helicopters Inc. of New Orleans has ordered 154 Model 206B‐III JetRanger and 206L‐III LongRanger aircraft for delivery between 1992 and 1995.

The purpose of this paper is to evaluate the impact on customer service of amalgamating two production/distribution facilities in a blood distribution network, located in the Maritime region of Canada, into a single production facility and a satellite distribution facility.

Simulation models of the existing distribution network and the future distribution network were built. Experiments were conducted, using the two models, to compare the performance of each.

Results indicate that there is no evidence to suggest a decrease in customer service resulting from the consolidation of the two facilities. Furthermore, results indicate that this conclusion is robust with respect to lower inventory levels at the satellite and up to three road closures per annum.

The results are based on specific operational assumptions regarding the number of hospitals supplied by the satellite facility and the methods used to transport blood products between locations.

The results of this study have important implications for how vital blood products are distributed to patients in the Maritime provinces of Canada.

This paper is a case study describing a unique application of simulation methods to an important area of application. It will be of interest to readers interested in the management of blood supply chains and to researchers applying simulation methods.