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“ASKA” developed by National Aerospace Laboratory (NAL) is a quiet, short take-off and landing (QSTOL) research aircraft adopting upper surface blowing (USB) concept as a powered high lift system. To achieving sufficient STOL performance by augmenting stall angle of attack and roll control power, blowing BLC technique was applied to the outboard leading edges and ailerons.Supplied high pressure air to save the BLC piping space,the BLC system which was fit for use of high pressure air was developed. The BLC system, in which BLC air is discharged by a series of discrete jets from small drilled holes (0.8 ∼ 3.0 mm in diameter) arranged in a raw, is one of the unique features of the aircraft. In this paper, the summaries of aerodynamic development of the BLC system are described except for the air piping system.

The Advanced ECS is under development for the purpose of saving fuel, improving safety, and cabin comfort. In FY2006 study, basic components (i.e. MDC, OBNOGS, desiccant units, and CO2 removers) have been improved and their performances evaluated including resistance to environmental condition (i.e. vibration). In addition, the suitable system configuration for a 90-seats aircraft has been considered to evaluate the feasibility of the system. In this paper, we show the results of the evaluated performances based on prototype components, and the analytical study of a revised system configuration.

The impact of inlet unstart phenomena on supersonic transport (SST) was investigated by wind tunnel testing. Inlet unstart condition was simulated by controlling the captured mass flow by the inlet. Unsteady pressures on the lower surface of wing and unsteady forces of the wind tunnel model were measured. Unsteady pressure measurement was carried out to detect shock wave motion. Unsteady force measurement by using both internal balance and accelerometers was to estimate axial/angular acceleration of airframe when inlet unstart was occurred. The pressure measurement data revealed that shock location fluctuated with dominant frequency although the controlled mass flow was steady. And it was analytically shown that the dominant frequency is corresponding to the first order frequency of organ pipe resonance.

Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) conducted vertical drop tests of fuselage sections of a NAMC YS-11 A-200 transport airplane. This test program is a part of research activities in NAL on the structural crashworthiness of transport aircraft. In addition a cooperative research related to this test program has been carried out by NAL and Kawasaki Heavy Industries, Ltd.(KHI). The main objectives of this program are to develop optimal numerical models for crash simulation of aircraft fuselage and to obtain background data by drop tests of full-scale fuselage sections under a controlled impact condition. Two sections of the fuselage structure with seats and passenger dummies were tested at different drop velocity to a rigid impact surface(concrete). Finite element models of the test articles for simulation of vertical drop tests were developed using a nonlinear dynamic analysis code, LS-DYNA3D.

The authors developed an air-to-air surveillance system that acquires mutual position and informs the position to the pilot. This system transmits position information obtained by GPS via TDMA (Time Division Multiple Access) datalink. Position information received from other aircraft is shown on a display. If proximity condition exists, voice alert is activated. This system can be used as an support system for collision avoidance. This paper describes the outline of the system and flight test result. Two prototype systems were installed on two helicopters. The third system was installed on a ground vehicle. Flight tests were performed using these three systems.

Motorcycle engines are operated at an extremely broad range of revolutions, from 1000 min-1 to 10000 min-1 or more. Ideally, the natural frequency of each part should never match the engine excitation frequency at any point over that entire range of revolution speeds, but practically, there are times when resonance cannot be avoided because the range is so broad, and therefore the vibration amplitude at resonance must be kept low. For this reason, it is important to grasp not only the resonance frequency but also the vibration amplitude at that point. This may be achieved by two methods, measurement and analysis. The direct measurement of vibration is generally difficult because the motorcycle muffler system has a complex shape and in addition it gets very high temperature when the engine is operating. For this reason, with the aim of being able to predict muffler vibration at the design stage, we carried out a vibration test and FEM (finite element method) analysis.

The Structures and Materials Research Center of the National Aerospace Laboratory of Japan (NAL) conducted a vertical drop test of a fuselage section from a NAMC YS-11 transport airplane in December2001. This test program is a part of research activities in NAL on the structural crashworthiness of transport aircraft. In addition a cooperative research related to this test program was carried out between NAL and Kawasaki Heavy Industries, Ltd.(KHI). The main objective of this program is to develop optimal numerical models for crash simulation of aircraft fuselage and to obtain background data by drop tests of small-scale structural models and a full-scale fuselage section. Prior to the drop test of a full-scale fuselage structure, a trial numerical simulation on the crash behavior of a small-scale sub-floor structure was conducted by NAL using the explicit, nonlinear dynamic analysis code, LS-DYNA3D.

The Japanese Quiet Short Take Off and Landing experimental aircraft named ASKA was developed and flight tested during 1977 till 1989. The control system hard and software were examined by the functional mock-up with using the actual hardware. The small longitudinal limit cycle was observed in the closed loop test when the Pitch Control Wheel Steering software was on in the mock-up testing. In this paper, first, the method to analyze and to expect the limit cycle based on the describing function was shown. The limit cycle was induced due to the nonlinearities in the automatic control mechanism. The nonlinearities in the hardware were examined to make the model to simulate the system on the computer. The method was shown effective to predict the limit cycle in the mock-up. Second, with using the flight measured dynamics, the limit cycle was concluded as on border line between existing and not, which coincides with the actual flight result.

In this study, we efficiently predict the vibration response of a design shape at a low computational cost in the early development stage, select design proposals with good characteristics from many proposals devised by the designer at the early stage, and forward them to the next stage to achieve the front-loading of development while increasing product value. The application of participation factor (PF) focusing on the response at a specific part for vibration evaluation of a motorcycle frame is described. To reduce the motorcycle frame vibration, an eigenvalue analysis was performed, and appropriate design change proposals were efficiently selected using partial participation factor (PPF), an index showing the relevance of vibration of specific parts or positions. Using the PPF, we extracted which vibration modes considerably contribute to the vibration response of the part of interest.

Hydraulic fluid (HF) specifications for mobile construction equipment called JCMAS HK and HKB have been established by the Fuels and Lubricants Committee of Japan Construction Mechanization Association (JCMA). The specifications are designated by two viscosity categories of single grade and multigrade. Each category has ISO viscosity grade (VG) 32 and 46. The JCMAS HK oils are recommended for use in hydraulic systems designed at pressure up to 34.3MPa(5000psi) and to heat hydraulic fluid up to 100 °C. These oils also provide wear control, friction performance, oxidation and rust protection, seal swell control and filterability performance. Two piston pump test procedures were developed to evaluate lubricating performance of these oils under high pressure conditions. The JACMAS HKB oils are classified as environmentally friendly oils due to the additional requirement for biodegradability.

A new 0.9-liter 4-valve-per-cylinder liquid cooled engine was developed for 1984 model motorcycles. This new engine was optimized from the standpoint of performance, durability, and weight efficiency. Semi-Flat slide carburetors, high compression ratio, relatively short stroke and large valves were employed. This engine was upgraded every other year with changes in displacement. Induction system, exhaust system, and valve train. This paper describes, from the viewpoint of the designer, the evolution of the 4-valve liquid-cooled engine from the 1984 to 1988 models. In that evolutionary process we employed: (1) semi-down draft carburetors with smooth air ducts, (2) a computer-aided intake and exhaust port design and manufacturing system. (3) individual rocker arms. (4) a cool air intake system. (5) lightweight pistons. (6) angle -controlled tightening of connecting rod bolts.

In the modern aircraft manufacturing, the cost reduction, the manufacturing time reduction, and the weight saving of aircraft are strongly demanded. The Refill Friction Spot Joining [1,2](FSJ, in other words FSSW, Friction Stir Spot Welding), which is one of innovative solid-state joining methodologies based on the Friction Stir Welding[3], is a promising technology that can replace rivets and fasteners. This technology is expected to offer cost reduction and weight saving for the aircraft manufacturing. In this study, to make stronger and reliable joints, the shoulder-plunging process of Refill FSJ was employed. The weldability of the Alodine or Chromic Acid Anodize coated materials along with a faying-surface sealant was investigated. The joint properties, such as tensile shear strengths and corrosion resistance, were evaluated.

This paper describes the predicted results of acoustic transmission loss (T.L.) for a motorcycle muffler. First, the T.L. of a prototype muffler with one expansion chamber was obtained by measuring sound levels at the inlet and outlet ports of the muffler by speaker test. T.L. was then calculated by using a three-dimensional Finite-Element Method (FEM) for acoustic fields in the muffler. There was good coincidence between the calculated T.L. and experimentally observed data. Second, T.L. of the prototype muffler while attached to a motorcycle engine was measured. On this step, however, a similarly calculated T.L. using FEM to consider the effect of exhaust gas temperature in the muffler showed differences from the measured one. It was estimated that muffler body vibration sounds may affect the result. A dynamic analysis of the structure was carried out using FEM to obtain the eigen modes of the muffler body.

The rocker arm has a function to lead the cam shaft rotation to the valve operation. There are cases when damages are caused due to abnormal wear at the sliding part, causing certain problems. Authors classified the wear phenomenon, and realized a systematic analysis on the possible cause of the damage. As a result, it was revealed that the damage was of two types, and to prevent the hard wear, it is effective to apply shot peening before plating. The prototype rocker arm was test under various lubricating conditions, thus actually confirming that the occurrence of wear was largely reduced.

A waterjet propulsor has come to be used more popularly for high speed watercrafts such as personal watercrafts. The most difficult problem for designing the waterjet system is that a tradeoff is required to properly determine the best parameters for the waterjet pump and subsequently the best overall propulsion system. This paper presents the design method and performance improvement of the waterjet propulsor used for personal watercrafts. The authors have clarified the performance of the individual component in the waterjet propulsor and improved the component efficiency empirically, and established the method to estimate the thrust and power characteristics of the propulsor on board from the component test results and other design parameters, which enables the optimization of the waterjet system.

Though most street-use motorcycles are now equipped with 4-stroke engines, off-road motorcycles, especially moto-cross racers, still mainly use 2-stroke engines because of their high power and light weight. 2-stroke engines for moto-cross racers require the engine characteristics of high power and excellent throttle response on a wide range of engine speeds. These characteristics immediately require an effective exhaust device to improve output performance at the middle-speed range while maintaining high power at the high-speed range. The latest 2-stroke engines maintain such performance by using an exhaust device, and also by the application of extensively improved basic elements such as the scavenging passage arrangement, exhaust timing and passage shape, etc. This paper briefly summarizes continuous efforts for the improvement of our exhaust-system device from its beginning until the present.

The traction-drive integrated drive generator (T-IDG®) has been developed since 1999 to replace current hydrostatic transmission drive generators mounted on Japanese military aircraft. The T-IDG® consists of a generator and a half-toroidal traction-drive continuously variable transmission (CVT), which maintains a constant output speed of 24000 rpm, that is, a 400 Hz AC power supply. To cope with recent trends of more electric aircraft (MEA) and the need for weight reduction, a high-speed traction-drive CVT is advantageous over other transmissions. The torque on the half-toroidal variator is transmitted through multiple power rollers. The equal load sharing among power rollers is typically controlled by a mechanical hydraulic feedback system, whose stability is one of the main issues for the high-speed traction-drive CVT. Previous studies have shown that insufficient damping and stiffness of the mechanical hydraulic feedback system cause self-induced vibration.

When an electronically controlled fuel injection device is located at downstream in intake port (hereinafter defined as downstream injection, on the other hand, upstream injection is defined as that fuel injection device is located at upstream in intake port), the possibilities of an improvement in the engine startability, increase in maximum power, and decrease in THC during warming have been reported in visualizations of the intake port. In addition, the amount of wall adhesion decreased with downstream injection in previous paper [1]. In this paper, we examine the influence on the amount of wall adhesion due to the difference in injection position on fuel transport in the intake port during transient operation and the obtained exhaust A/F and the amount of exhaust gas emitted during transient operation are evaluated.

As for automobile, the mass production period of Electric Vehicle(EV) has begun by the rapid progress of the battery performance. But for EV-Motorcycle(MC), it is limited for the venture companies' releases. The design and evaluation methodologies are not yet established or standardized so far. This paper provides the practical and the experimental examples. To study the feasibility of EV-MC, we developed the prototypes in the present technical and suppliers' parts environments, and evaluated them by the practical view of the MC usage. The developed EV-MC has the equivalent driving performance of the 250cc internal combustion engine(ICE)-MC and a cruising range of 100km in normal use.

Electroimpact and Kawasaki Heavy Industries (KHI) have produced a new riveting process for the forming of Briles type rivets in Boeing 777 and 777X fuselage assemblies. The Briles rivet is typically used for fuselage assembly and is unique in that it has a self-sealing head. Unlike conventional headed rivets such as the NAS1079, this fastener does not require aircraft sealant under the head to be fluid tight. This unique fastener makes for a difficult fastening process due to the fact that interference must be maintained between the hole and fastener shank, as well as along the sides of the fastener head. Common issues with the formed fasteners include gapping under the fastener head and along the shank of the fastener. Electroimpact has employed a host of different technologies to combat these issues with Briles fastening. First, Electroimpact’s patented “Air Gap” system allows the machine to confirm that the head of the rivet is fully seated in the countersink prior to forming.