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Computer Aided Engineering (CAE), together with CAD (Computer Aided Design) and CAM (Computer Aided Manufacturing), is an effective tool to shorten the product development cycle, to decrease the cost, and to improve the product quality of full vehicle development programs. Faster computers, cost effective hardware, and advanced software technology have accelerated CAE technology to the point that a new approach to simulating proving ground test conditions has been developed and implemented for full vehicle development programs. This paper discusses this new and integrated approach, called Virtual Proving Ground (VPG), and includes studies of Road Load Generation, Durability, Vehicle Crashworthiness, Occupant Safety, and Noise/Vibration/Harshness (NHV).

This paper outlines open architecture PC (personal computer) based controls for automotive manufacturing environment. Generally a PC based control system utilizes DOS (or similar operating system) based computers (Industrially hardened AT or compatible computer), instead of a PLC (programmable logic controller), to operate machinery, and control program execution. It is based on an open architecture, allowing the ease of selecting any vendor platform, and allowing complete exchanges between platforms, without costly re-development and conversion down time. With factory floor networks and sensor buses, I/O operability has become very standardized. Information, and action can be fed backwards and forwards, to allow devices to react to messages in a simplified fashion. Reduced wiring costs, and high speed make such networks viable options for the manufacturing design groups. Automotive throughput has been seen to increase by two-folds with such innovative exercises.

With the evolution of Electronics, the Vehicle Security System has undergone a sea change and has taken a complex shape. Therefore, both the owner as well as service technicians have to become more aware and develop better understanding of the various systems and procedures involved in Security Systems. This paper will deal with the Electronics aspect of the Vehicle Security System.

In this paper, the development possibilities for all transport vehicles of the next millennium, employing monocoque and semi-monocoque bodies in advanced composites, is highlighted. The possible adoption of Fibre Reinforced Plastics (FRP) for such monocoque and semi-monocoque bodies is demonstrated through the lab developments of (i) a semi-monocoque shell and (ii) a vehicle panel in glass FRP in an Autoclave under vacuum bagging. The required shear flow calculations and Finite Element Analysis results, tabulated and plotted, as a case study for such monocoque shell construction concept, are presented in this paper for ready reference.

There are many aspects of engineering integrity which require careful consideration during design, manufacture, operation and maintenance of the complex systems such as automobile. The ultimate realisation of the “goals of design” implies successful service during the entire life of the product. There is tremendous pressure to utilise lighter materials which results in fuel saving. Assessing the engineering integrity of components and systems under service conditions can be extremely complex and prognostic situation at design stage is often more difficult than the diagnostic one once failure has occurred. Review of various advanced techniques with case studies have been done for the safety and reliability of automobiles for Indian conditions.

With increasing competition and globalization, the Indian Tractor Industry is gearing up to develop new proven design of tractors. The conventional methodology of trial and error design and its proving is becoming obsolete and practically too time consuming to meet the demands. Many designers are already in need of field data as the base for design. Prototype proving and reliability testing of the components and tractors in the laboratory has become the need of the day. All these requires quantification of service loads in the Laboratory. This paper describes in brief the methodology of these exercises, selection of instrumentation and data acquisition systems, typical problems of data acquisition on the tractors, based on the experience. This paper also provides illustrative examples of data acquisition and typical applications of the acquired data.

Collection efficiency and ice accretion calculations have been made for a Boeing 737-300 inlet using a three-dimensional panel code, an adaptive grid code, the NASA Lewis LEWICE3D grid based ice accretion code. Flow solutions for the inlet were generated using the VSAERO panel code. Grids used in the ice accretion calculations were generated using the newly developed adaptive grid code ICEGRID3D. The LEWICE3D grid based ice accretion program was used to calculate impingement efficiency and ice shapes. Ice shapes typifying rime and mixed icing conditions were generated for a 30 minute hold condition. All calculations were performed on an SGI Power Challenge computer. The results have been compared to experimental flow and impingement data. In general, the calculated flow and collection efficiencies compared well with experiment, and the ice shapes looked reasonable and appeared representative of the rime and mixed icing conditions for which they were calculated.

Two cases of unusual inflight icing encountered by turbine engine-powered airplanes are discussed. The atmospheric conditions in which the apparent icing occurred are unusual in that in both cases the temperature was colder than that typically associated with icing (at the altitudes at which the events occurred). The pilots' accounts of the events suggest that large supercooled droplets were encountered. These conditions are rare at any temperature, but especially at the temperatures at which these events occurred.

The KEEP EAGLE flight test program was conducted from August 1994 until August 1995 at Edwards AFB by a combined government/contractor test team to evaluate improvements to F-15E high angle-of-attack and spin recovery characteristics. This paper will trace the program from its inception in 1992 until conclusion in 1995, with emphasis on the test approach and flight test techniques employed for this high risk program. Specifically, the test approach included novel assessments of spin recovery control power early in the flight test program using controlled build-ups in yaw rate. The program also used simulation effectively to improve test efficiency and maintain test team proficiency with normal and emergency procedures. These techniques allowed a relatively aggressive flight test program without compromising safety. A total of 18 different aircraft configurations were successfully tested, with 146 developed spins completed throughout the course of 81 program flights.

A cockpit revolution is in the making. Many of the much ballyhooed, much promisemd, but little delivered technologies of the 70's and 80's will finally come of age in the 90's just in time to complement the data explosion coming from sensor and processor advances. Technologies such as helmet systems, large flat panel displays, speech recognition, color graphics, decision aiding and stereopsis, are simultaneously reaching technology maturities that promise big payoffs for the third generation cockpit and beyond. The first generation cockpit used round dials to help the pilot keep the airplane flying right side up. The second generation cockpits used Multifunction Displays and the HUD to interface the pilot with sensors and weapons. What might the third generation cockpit look like? How might it integrate many of these technologies to simplify the pilots life and most of all: what is the payoff?

Current US military specifications for cockpit design reflect all of the ‘evils’ that gave impetus to current DoD specification reform initiatives. These old specifications define a ‘bottom up’ approach to cockpit design by emphasizing detail design requirements for cockpit components and subsystems. The cockpit itself is not considered a system which results in poorly integrated cockpits that do not meet user needs. Specification reform has led to major joint service initiatives to correct these deficiencies. A cockpit performance guide specification is in development to address performance requirements and related design guidance for the cockpit and its numerous interfaces.

By applying Knowledge-based Engineering (KBE) technology, the Gear Train design process at AlliedSignal Engines has realized an overall productivity improvement of 2:1. The traditional process requiring over 800 man-hours in 15 calendar weeks, has been reduced to 400 man-hours in 8 calendar weeks. With the KBE application, “Users” manipulate “objects” that encapsulate Design, Analysis, and Manufacturing rules and processes from company domain experts. The interaction and resolution of multiple domain rules within the application to achieve top-level constraints yields a design instance satisfying Engineering and Manufacturing requirements. The application has been used successfully to respond to proposals and evaluate gear train configurations without requiring large teams and all the associated hand-offs, while still allowing best practices from multiple disciplines to be applied consistently.

A design procedure is presented which utilizes (1) the active control technologies such as Flutter Mode Control, Gust Load Alleviation and Maneuver Load Control to relax the strength and stiffness requirements on wing structure, and (2) structural optimization to derive the minimum weight composite wing structures satisfying the relaxed structural requirements. The design procedure is applied to the preliminary design study of a Supersonic Commercial Transport configuration with laminated composite wing structure. Four design configurations are compared. Maximum of about 30% structural weight reduction was achieved from the quasi-isotropic design. Also some insights on the characteristics of the Supersonic Commercial Transport configuration are discussed.

Forming of metal is a very challenging problem. To optimize a particular forming process the manufacturing engineer needs to determine the relationship between several dependent material properties and the independent forces on the metal that are generated by the press and tooling. The classical method to optimize a forming process relies on experience and trial and error development techniques. The forming of aluminum, when compared to steel, requires more development work to optimize the forming process. Finite element analysis provides a method to quickly perform the trial and error iterations necessary to optimize the forming of aluminum.

A preliminary study of structural concepts for non-circular fuselage configurations is presented. For an unconventional flying-wing type aircraft, in which the fuselage is inside the wing, multiple fuselage bays with non-circular sections need to be considered. In a conventional circular fuselage section, internal pressure is carried efficiently by a thin skin via hoop tension. If the section is non-circular, internal pressure loads also induce large bending stresses. The structure must also withstand additional bending and compression loads from aerodynamic and gravitational forces. Flat and vaulted shell structural configurations for such an unconventional, non-circular pressurized fuselage of a large flying-wing were studied. A deep honeycomb sandwich-shell and a ribbed double-wall shell construction were considered. Combinations of these structural concepts were analyzed using both analytical and simple finite element models of isolated sections for a comparative conceptual study.

The problem of decreasing separation distances between aircraft during their takeoffs and landings is investigated. This work presents a general view on the problem under study, whose complexity lies basically in the fundamental impossibility to create a single method and universal tool of investigation. A fragmentary approach is used with asymptotically non-strict splitting of the problem into several subproblems. The formulations of the subproblems are considered, the potentialities of the research tools are assessed, the ways and phases of model refinement are outlined. Some concrete measures are discussed for decreasing safe separation distances between aircraft.

This paper presents the design evolution of a military transatmospheric aerospace plane, considerations of options, and the formulation of a single transatmospheric aerospace plane. The design concept started with requirements, an operational concept, a set of design choices, a technology base, and a close look at the factors that determine orbital closure performance requirements. Several unique factors are considered in the design formulation. The baseline mission is a once around and return to the base from which the takeoff occurred. The flight profile to minimize energy requirements is a boost-glide-skip-glide trajectory. The configuration is based on recent work at the University of Maryland on waverider optization across a range of Mach numbers. Engine selection is based on both specific impulse and engine thrust to weight for a rocket-based combined cycle engine. The Aerojet “strut rocket” combined-cycle engine is baselined.

Flight experiments were conducted on an instrumented NASA-Langley 737-100 aircraft to investigate high-lift flow physics and to correlate and validate computational and wind-tunnel measurements. The possible reversion of turbulent attachment-line flow present at flight Reynolds numbers to a laminar state (relaminarization), under the action of strong favorable pressure gradients, has a potentially significant impact on the prediction of high-lift system performance from wind-tunnel tests and computational analyses. Boundary-layer state measurements, obtained in the most recent flight phase, taken around the slat and leading edge of the main element, are analyzed. Three transition processes on the slat (attachment-line transition, boundary-layer relaminarization, and subsequent retransition) are studied with and without a boundary-layer trip (trip belt) to vary attachment-line disturbance levels and to test the relaminarizing tendencies of the slat.