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The 1-D model of a radial centripetal turbine was developed for engine simulation to generalize and extrapolate the results of experiments to high pressure ratio or off-design velocity ratio using calibrated tuning coefficients. The model concerns a compressible dissipative flow in a rotating channel. It considers both bladed or vaneless turbine stators and a twin-entry stator for exhaust pulse manifolds. The experiments were used to find values of all model parameters (outlet flow angles, all loss coefficients including an impeller incidence loss) by an original method using repeated regression analysis. The model is suitable for the prediction of a turbocharger turbine operation and its optimization in 1-D simulation codes.

In recent years, improvements in the fuel economy and exhaust emission performance of internal combustion engines have been increasingly required by regulatory agencies. One of the salient concerns regarding general purpose engines is the larger amount of CO emissions with which they are associated, compared with CO emissions from automobile engines. To reduce CO and other exhaust emissions while maintaining high fuel efficiency, the optimization of total engine system, including various design parameters, is essential. In the engine system optimization process, cycle simulation using 0-D and 1-D engine models are highly useful. To define an optimum design, the model used for the cycle simulation must be capable of predicting the effects of various parameters on the engine performance. In this study, a model for predicting the performance of a general purpose SI (Spark Ignited) engine is developed based on the commercially available engine simulation software, GT-POWER.

In many countries of the world, carburetor motorcycles are the major transportation system for people. The large volumes of these motorcycles contribute to high levels of urban emissions and this fact promotes the relevant emissions regulations to become more stringent. This paper presents an approach to satisfy various new emissions regulations such as Euro-III and Taiwan 4th generation emissions regulations by optimizing the 4-stroke PFI (Port Fuel Injection) engine management system (EMS) and after-treatment system.

A first attempt to study civil aircraft operations comprehensively, prior to having the airplane, occurred before the initial operation of U.S. subsonic jets. One airline carried out a manual-simulated “paper jet” operation lasting fifteen months. Today, computerized simulation of machines, methods, and operations has become commonplace, and replaces the slide rule and tedious day-by-day inputs of aircraft operational criteria. Computerized simulations are also applied to every aspect of the SST design and operations. These are important, but the results being should be used with caution and judgement.

This paper presents a summary of body structural analysis applied to the 1989 Suzuki Sidekick/Geo Tracker at various stages of development and design. The structure analysis techniques were applied previously to rigidity, vibration, strength, crashworthiness and optimization. The studies confirm that the CAE technique for body structure analysis is more beneficial if it is utilized in the earlier structure development stages particularly for vibration and crashworthiness. Through the extensive use of the structural analysis technique in conjunction with the experiment, the design concept of the Sidekick/Tracker body has been optimized to a most extent.

The Cardinal is a Super Short Takeoff and Landing (SSTOL) aircraft, which is designed to fulfill the desire for center-city to center-city travel by utilizing river “barges” for short takeoffs and landings to avoid construction of new runways or heliports. In addition, the Cardinal will fulfill the needs of the U.S. Navy for a Carrier On-board Delivery (COD) aircraft to replace the C-2 Greyhound. Design requirements for the Cardinal included a takeoff ground roll of 300 ft, a landing ground roll of 400 ft, cruise at 350 knots with a range of up to 1500 nm with reserves, payload of 24 passengers and baggage for a commercial version or a military version with a 10,000 lb payload, capable of carrying two GE F110 engines for the F-14D, and a spot factor requirement of 60 feet by 29 feet.

Most of current jet aircraft circulate fuel on the airframe to match heat loads with available heat sink. The demands for thermal management in wide range of air vehicle systems are growing rapidly along with the increased mission power, vehicle survivability, flight speeds, and so on. With improved aircraft performance and growth of heat load created by Aircraft Mounted Accessory Drive (AMAD) system and hydraulic system, effectively removing the large amount of heat load on the aircraft is gaining crucial importance. Fuel is becoming heat transfer fluid of choice for aircraft thermal management since it offers improved heat transfer characteristics and offers fewer system penalties than air. In the scope of this paper, an AMESim model is built which includes airframe fuel and hydraulic systems with AMAD gearbox of a jet trainer aircraft. The integrated model will be evaluated for thermal performance.

This paper presents 1D engine simulation used for engine control strategy optimization for a twin-scroll turbocharged gasoline direct injection 2.0 L engine with twin camphaser. The results show good agreement of the engine model behavior with testbed acquisitions for a large amount of steady state set points and under transient operating conditions. The presented method demonstrates that a 1D engine code represents a useful and efficient tool during all steps of the engine control development process from design to real-time for such an advanced engine technology.

Handling performance of a vehicle is a key characteristic determining the response of vehicle under different operating scenarios. An insight into these vehicle-handling characteristics at early stage can be extremely useful in the design and development process. Tire characterization and tuning is important and mandatory to scrutinize each functional and individual parameter of tire. Tire force and moment data is having a significant effect in vehicle handling. Segregation of tire parameter, which is contributing vehicle-handling performance, helps to identify and perform optimization for improvisation. The main objective of this study is development and integration optimized 1D tire model into multibody dynamics model of the vehicle to observe various vehicle compliances towards its handling performance target.

The paper presents a numerical study aimed at converting a commercial lightweight 2-Stroke Indirect Injection (IDI) Diesel aircraft engine to Direct Injection(DI). First, a CFD-1D model of the IDI engine was built and calibrated against experiments at the dynamometer bench. This model is the baseline for the comparison between the IDI and the DI combustion systems. The DI chamber design was supported by extensive 3D-CFD simulations, using a customized version of the KIVA-3V code. Once a satisfactory combustion system was identified, its heat release and wall transfer patterns were entered in the CFD-1D model, and a comparison between the IDI and the DI engine was performed, considering the same Air-Fuel Ratio limit. It was found that the DI combustion system yields several advantages: better take-off performance (higher power output), lower fuel consumption at cruise conditions, improved altitude performance, reduced cooling requirements.

The paper describes a numerical study, supported by experiments, on light aircraft 2-Stroke Direct Injected Diesel engines, typically rated up to 110 kW (corresponding to about 150 imperial HP). The engines must be as light as possible and they are to be directly coupled to the propeller, without reduction drive. The ensuing main design constraints are: i) in-cylinder peak pressure as low as possible (typically, no more than 120 bar); ii) maximum rotational speed limited to 2600 rpm. As far as exhaust emissions are concerned, piston aircraft engines remain unregulated but lack of visible smoke is a customer requirement, so that a value of 1 is assumed as maximum Smoke number. For the reasons clarified in the paper, only three cylinder in line engines are investigated. Reference is made to two types of scavenging and combustion systems, designed by the authors with the assistance of state-of-the-art CFD tools and described in detail in a parallel paper.

The General Motors (GM) Corvette design team was challenged with providing a C6 Z06 vehicle spaceframe that maintained the structural performance of its C5 predecessor while reducing mass by at least 56 kg. An additional requirement inherent to the project was that the design must be integrated into the C6 assembly processes with minimal disruption, i.e. seamless integration. In response to this challenge, a collaborative team was formed, consisting of design engineers from General Motors, Alcoa and Dana Corporation. The result of this collaborative effort is an aluminum Z06 spaceframe that satisfies the high performance expectations of the vehicle while reducing the mass by approximately 62 kg. The frame consists of aluminum extrusions, castings and sheets joined by MIG welding, laser welding and self-piercing rivets. The extrusions are 6XXX series alloys, the castings are permanent mold A356 while the sheet panels are formed from the 5XXX series of alloys.

General Motor's Corvette product engineering was given the challenge to find mass reduction opportunities on the painted body panels of the C6 Z06 through the utilization of carbon fiber reinforced composites (CFRC). The successful implementation of a carbon fiber hood on the 2004 C5 Commemorative Edition Z06 Corvette was the springboard for Corvette Team's appetite for a more extensive application of CFRC on the C6 Z06 model. Fenders were identified as the best application for the technology given their location on the front of the vehicle and the amount of mass saved. The C6 Z06 CFRC fenders provide 6kg reduction of vehicle mass as compared to the smaller RRIM fenders used on the Coupe and Convertible models.

The 2013 SRT Viper Carbon Fiber X-Brace, styled by Chrysler's Product Design Office (PDO), is as much of a work of art as it is an engineered structural component. Presented in this paper is the design evolution, development and performance refinement of the composite X-Brace (shown in Figure 1). The single-piece, all Carbon Fiber Reinforced Plastic (CFRP) X-Brace, an important structural component of the body system, was developed from lightweight carbon fiber material to maximize weight reduction and meet performance targets. The development process was driven extensively by virtual engineering, which applied CAE analysis and results to drive the design and improve the design efficiency. Topology optimization and section optimization were used to generate the initial design's shape, form and profile, while respecting the package requirements of the engine compartment.

The U. S. Coast Guard has recently put into service new 210 ft cutters designed for search and rescue work, law enforcement, oceanographic work, and possible future ASW. This paper outlines the structure and capabilities of the vessel. An important feature of the cutter is its helicopter handling facilities, which have greatly increased the cutter's search and rescue capability by extending the area it can cover. The cutter is the first in Coast Guard service to be powered by a combination diesel engine and gas turbine installation. The combination gives a top speed of 18 knots and a cruising range of 5000 miles.

Aircraft potable (drinking) water systems haven’t changed significantly in the last half-century. These systems consist of cylindrical water tanks pressurized by bleed air from the jet engines, with insulated stainless steel distribution lines. What has changed recently is the increase in the possibility of aircraft picking up contaminated drinking water at foreign and domestic stops. Customer awareness of these problems has also changed - to the point where having reliable drinking water is now a competitive issue among airlines. Old style potable water systems that are used on modern aircraft are high maintenance and exacerbate the growth of microbes because the water is static much of the time. The integrity of some pressurized water tanks are also a concern after years of use. Cost-effective mechanical and biological solutions exist that can significantly reduce the amount of chemicals added and provide good potable water.

The need for efficient space utilization has provided a framework for the design of a 248mm family of torque converters that supports a wide choice of engine and transmission combinations. The axial length of the part and its weight have been substantially reduced while the performance range has been broadened without degradation of efficiency. The new converter operates in an expanded slipping clutch mode. It significantly contributes to the performance and fuel economy improvements of related vehicles. To meet the cost target, the comprehensive lineup and the resulting complexity have required a high level of component interchangeability. During the design phase, the manufacturing core competencies were scrutinized and process redundancies eliminated, both resulting in optimization of material selection and applicable technology.

Preliminary results from testing of 26 X 6.6 radial-belted and bias-ply aircraft tires at NASA Langley's Aircraft Landing Dynamics Facility (ALDF) are reviewed. These tire tests are part of a larger, on going joint NASA/FAA/Industry Surface Traction and Radial Tire (START) Program involving three different tire sizes. The 26 X 6.6 tire size evaluation includes cornering performance tests throughout the aircraft ground operational speed range for both dry and wet runway surfaces. Static test results to define 26 X 6.6 tire vertical stiffness properties are also presented and discussed.

Sundstrand is investigating 270-Vdc/hybrid 115-Vac electrical power generating and distribution systems technology so as to be well prepared to offer such systems for future aircraft applications. The approach taken has been to design, build, and test a representative system that meets or exceeds the tightest of the performance standards as defined by miliary standards. This paper describes a single-channel, 120-kW hybrid system and presents some typical performance data. The dc bus supplies a 30-kVA, 400-Hz, 115-Vac inverter; constant power load banks of up to 150 kW; and a resistive load bank of up to 90 kW. System simulation studies indicated the potential for unstable operation due to the negative impedance of the constant power load in conjunction with the source ripple filter and the load EMI filters. Unstable voltage and current were observed in system testing when the magnitude of the source impedance was not sufficiently below that of the load impedance.

Sundstrand has been investigating 270-Vdc/hybrid 115-Vac electrical power generating systems (EPGS) technology in preparation for meeting the electrical power generating system (EPGS) requirements for future aircraft (1). Systems such as the one being investigated are likely to be suitable for the More-Electric Aircraft (MEA) concepts presently under industry and military study. The present Sundstrand single-channel testbed is being further expanded to better understand the electrical system performance characteristics and power quality requirements of an MEA in which traditional mechanical subsystems are replaced by those of a “more-electric” nature. This paper presents the most recent Sundstrand 270-Vdc system transient performance data, and describes the modifications being made to the 270-Vdc/hybrid 115-Vac testbed.