Search Results

Composite materials, pioneered by aerospace engineering due to their lightweight, strength, and durability properties, are increasingly adopted in the high-performance automotive sector. Besides the acknowledged composite components’ performance, enabled lightweighting is becoming even more crucial for energy efficiency, and therefore emissions along vehicle use phase from a decarbonization perspective. However, their use entails energy-intensive and polluting processes involved in raw material production, in manufacturing processes, and, in particular, in end-of-life disposal. Carbon footprint is the established indicator to assess the environmental impact of climate-changing factors on products or services. Research on different carbon footprint sources reduction is increasing, and even the European Composites Industry Association is demanding the development of specific Design for Sustainability approaches.

Emission regulations are becoming more stringent, as global temperature continues to rise due to the increasing greenhouse gases in the atmosphere. Battery electric vehicles (BEV), which have zero tailpipe emissions, are expected to become widespread to solve this problem. As the powertrain of BEV is more efficient than conventional powered vehicles, the proportion of energy loss during driving due to aerodynamic drag becomes greater. Therefore, reducing aerodynamic drag for improved energy efficiency is important to extend the pure electric range. At Honda, Computational Fluid Dynamics (CFD) and wind tunnel testing are used to optimize vehicle shape and reduce aerodynamic drag. Highly accurate CFD is essential to efficiently guide the development process towards reducing aerodynamic drag. Specifically, the prediction accuracy for the exterior shape, underfloor devices, tires, and wheels must meet development requirements.

Carbon dioxide removal from the Space Station Freedom atmosphere is an essential part of the crew's life support. Freedom must utilize carbon dioxide removal systems to prevent crew asphyxiation. This paper describes the design and development of the blower selected to operate as an essential part of the carbon dioxide removal assembly (CDRA) system. The blower drives the process air through the CDRA, enabling the carbon dioxide laden air to contact the absorbing material. Multiple-speed blower operation is utilized to optimize carbon dioxide removal. A mixed-flow blower was selected as the optimum design to meet the CDRA application requirements. The prime reasons for this selection are the unit's low weight, small size, and outstanding efficiency. In addition, the blower unit is equipped with air bearings for extremely long life.

Multi-Layer Insulation (MLI) is the thermal insulation typically used in spacecraft or any other devices that are exposed to both extreme heat and cold. MLI blankets work to protect delicate internal and external applications from UV radiation, atomic oxygen, and mechanical stresses by using Teflon coated fiberglass cloth. The layers are usually made of a film made out of polyester or polyimide with vapor deposited layers of aluminum on one or both sides of the film to form reflector layers. These reflectors are separated by materials with low thermal conductivity. All the layers simply protect the system by preventing excessive heat loss from inner components and excessive heating from outer sources. Typically, MLI blankets are divided into a cover or outer layer, a reflector, a separator layer, an inner layer, and it has hardware installed to pass electrical charge from the surface of the blanket.

As the automotive industry accelerates its virtual engineering capabilities, there is a growing requirement for increased accuracy across a broad range of vehicle simulations. Regarding control system development, utilizing vehicle simulations to conduct ‘pre-tuning’ activities can significantly reduce time and costs. However, achieving an accurate prediction of, e.g., stopping distance, requires accurate tire modeling. The Magic Formula tire model is often used to effectively model the tire response within vehicle dynamics simulations. However, such models often: i) represent the tire driving on sandpaper; and ii) do not accurately capture the transient response over a wide slip range. In this paper, a novel methodology is developed using the MF-Tyre/MF-Swift tire model to enhance the accuracy of ABS braking simulations.

COMPARISONS are drawn, in this paper, between engine supercharger and cabin supercharger flow-control problems. Some new methods of obtaining efficient flow control are discussed. Interdependent factors existing between flow control and impeller speed control must be recognized. It is pointed out that design features in the supercharger should be correlated closely with the type of control applied. Effects arising from the connection of superchargers to receivers of large volume are presented. Necessity for regulation of flow, pressure, and rate of pressure change in pressure cabins requires the solution of numerous new problems. The advantage of simultaneous design of the supercharger and controls, and the desirability of integral supercharger and control units, are stressed. It has been necessary to overcome many mechanical problems in order to produce units of a type suited for pressure cabin operation. Typical control constructions are described.

Squeak and rattle (SAR) noise audible inside a passenger car causes the product quality perceived by the customer to deteriorate. The consequences are high warranty costs and a loss in brand reputation for the vehicle manufacturer in the long run. Therefore, SAR noise must be prevented. This research shows the application and experimental validation of a novel method to predict SAR noise on an actual vehicle interior component. The novel method is based on non-linear theories in the frequency domain. It uses the harmonic balance method in combination with the alternating frequency/time domain method to solve the governing dynamic equations. The simulation approach is part of a process for SAR noise prediction in vehicle interior development presented herein. In the first step, a state-of-the-art linear frequency-domain simulation estimates an empirical risk index for SAR noise emission. Critical spots prone to SAR noise generation are located and ranked.

As environmental concerns have taken the spotlight, electrified powertrains are rapidly being integrated into vehicles across various brands, boosting their market share. With the increasing adoption of electric vehicles, market demands are growing, and competition is intensifying. This trend has led to stricter standards for noise and vibration as well. To meet these requirements, it is necessary to not only address the inherent noise and vibration sources in electric powertrains, primarily from motors and gearboxes, but also to analyze the impact of the spline power transmission structure on system vibration and noise. Especially crucial is the consideration of manufacturing discrepancies, such as pitch errors in splines, which various studies have highlighted as contributors to noise and vibration in electric powertrains. This paper focuses on comparing and analyzing the influence of spline pitch errors on two layout configurations of motor and gearbox spline coupling structures.

There are several relatively new certification standards related to Integrated Modular Avionics (IMA) certification that have recently been invoked by the certification authorities. These standards include SAE ARP-4754A, Guidelines for Development of Civil Aircraft and Systems, RTCA DO-297, Integrated Modular Avionics (IMA) Development Guidance and Certification Considerations, and RTCA DO-178C, Software Considerations in Airborne Systems and Equipment Certification. RTCA DO-254, Design Assurance Guidance for Airborne Electronic Hardware, and TSO C153, Integrated Modular Avionics Hardware Elements, are also applicable to IMA certification. As many of these standards have only recently been invoked in Advisory Circulars by the Certification Authorities, the industry has little experience in complying with them individually, and even less experience complying with them collectively.

Sustainability is both an ethical responsibility and business concern for the aerospace industry. Military and commercial avionics developers have pushed toward a common standard for interfaces, computing platforms, and software in hopes of having “reusability” and reducing weight with backplane computing architectures which, in theory, would support commonality across aircraft systems. The integrated modular avionics (IMA) and military Future Airborne Capability Environment (FACE) standards are two such examples. They emerged to support common computing architectures for reuse and sustainability concepts, from the beginning of aircraft development to the sundown or mortality phase. Pitfalls of Designing, Developing, and Maintaining Modular Avionics Systems in the Name of Sustainability looks at technological, organizational, and cultural challenges making reuse and IMA platform models difficult to fully realize their sustainability goals.

15-5PH is a precipitation-hardening, martensitic stainless steel used for primary structural elements such as engine mounts where corrosion resistance, high strength, good fatigue and fracture toughness is required. The material composition is defined in AMS5659M. This alloy can be either Type 1 - vacuum arc remelt (VAR) or Type 2 - electro slag remelt (ESR) and is most commonly heat treated per SAE AMS-H-6875 or AMS2759/3 to condition H1025 (an ultimate tensile strength of 155 ksi [1070 MPa] minimum). Typically material handbooks have limited fatigue data and most data is only for Type 1. Therefore, the fatigue properties of 15-5PH H1025 stainless steel for both Type 1 and Type 2 were determined. The objective of the fatigue testing was to generate a family of S-N curves (maximum stress versus number of cycles to failure) for a series of stress ratios across the entire range of cycles to failure.

The continuing development of the F-15 has included improvements to its baseline Environment Control System (ECS), an open air cycle system built around a bootstrap air cycle machine. A simple air controller schedule change and the conversion to a High Pressure Water Separator (HPMS) ECS were steps in the evolution of the F-15 ECS which yielded gains in avionics cooling capacity of about 63%. Although there was no associated capacity increase, optimization of the cooling air distribution system was done to improve avionic reliability. Recent modifications of the F-15E aircraft to accommodate the Increased Performance Engines (IPE) have included ECS changes to maintain the capacity gains achieved previously. The higher bleed pressures and temperatures characteristic of the IPE have necessitated new pressure regulators, ducts, and heat exchangers. External scoops have been added to improve ram cooling airflow.

The importance of fuel costs provide a strong incentive to operate the SST on existing jet fuels. Potential fuel system problems peculiar to the supersonic transport such as fuel boiling, spontaneous ignition, deposit formation, lubricity, and combustion characteristics are reviewed. The significance of these problems is established. Their severity depends on the particular environment provided by the designer. The difficulties of defining fuel properties to eliminate these problems are covered. The paper shows that major steps have been taken to operate the SST on current quality jet fuels but all necessary fuel quality control tests are not yet available.

Aerospace Recommended Practice (ARP) 4754 Revision A (ARP4754A), “Guidelines for Development of Civil Aircraft and Systems,” [1] is recognized through Advisory Circular (AC) 20-174 (AC 20-174) [2] as a way (but not the only way) to provide development assurance for aircraft and systems to minimize the possibility of development errors. ARP4754A and its companion, Aerospace Information Report (AIR) 6110, “Contiguous Aircraft/System Development Process Example,” [3] primarily describe development processes for an all new, complex and highly integrated aircraft without strong consideration for reused systems or simple systems. While ARP4754A section 5 mentions reuse, similarity, and complexity, and section 6 is intended to cover modification programs, the descriptions in these sections can be unclear and inconsistent. The majority of aircraft projects are not completely new Products nor are they entirely comprised of complex and highly integrated systems.

In recent years, the burgeoning applications of hydrogen fuel cells have ignited a growing trend in their integration within the transportation sector, with a particular focus on their potential use in multi-rotor drones. The heightened mass-based energy density of fuel cells positions them as promising alternatives to current lithium battery-powered drones, especially as the demand for extended flight durations increases. This article undertakes a comprehensive exploration, comparing the performance of lithium batteries against air-cooled fuel cells, specifically within the context of multi-rotor drones with a 3.5kW power requirement. The study reveals that, for the specified power demand, air-cooled fuel cells outperform lithium batteries, establishing them as a more efficient solution.