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With an increasing number of vehicles, the reduction of traffic noise emissions becomes a greater social requirement. On the other hand, as users' tastes for motorcycles have diversified, it becomes important to develop and supply products to meet customers' requests within a short period. Therefore, it is a key factor to efficiently develop motorcycles which conform to the noise regulations. This paper describes concrete examples of currently utilized noise-source proving methods and noise reduction methods for motorcycles.

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.

“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.

At the upstream part of the Three-Way Catalyst (TWC) an O₂ sensor (UpO₂S) is used for O₂ Feedback Control (O₂F/B) that controls the air-fuel ratio (A/F) close to the stoichiometric level. O₂ sensor has a bit of individual characteristic difference as for the switching the excess air ratios of output (λ shift). This phenomenon becomes remarkable according to the effects of unburnt elements in exhaust gas. Despite the O₂F/B implementation, A/F isn't controlled to the stoichiometric level and the conversion efficiency of the TWC could be lower. Maintaining a higher level of TWC conversion efficiency requires more accurate A/F control and corrections of the UpO₂S λ shift issue. Therefore, using an O₂ sensor at the downstream part of the TWC (DownO₂S)~where the effects of unburnt elements in exhaust gas are smaller~can be an effective way to restore these challenges.

The regulation for emission gas of the motorcycle is rapidly being strengthened as the concern about global environment grows around the world, and manufacturers are facing the problem to reduce the toxic materials in the emission gas more. As the technology to reduce the toxic materials, it is common to install a three way catalyst (TWC) on an exhaust system and optimize the oxygen concentration at the inlet of TWC by maintaining air fuel ratio (A/F) on stoichiometric A/F with the control of fuel injection quantity. Furthermore, TWC itself is designed to maintain proper oxygen concentration by the addition of a substance with oxygen storage capacity (OSC), which is able to suppress the variation of the oxygen concentration.

In the closed environments, removal of trace contaminants generated from persons, animals, and plants is important function to keep the environment below the allowable level. We conducted the fundamental tests in order to confirm design of TCCA (Trace Contaminants Control Assembly) for Closed Ecology Experiment Facilities (CEEF), and obtained the following results; 1) The palladium-on-alumina catalyst is suitable for CO, CH4, C2H4 conversion at temperature lower than 400°C. 2) The alkali impregnated AC (activated charcoal) is effective for NO2, SO2 removal and prevents catalyst poisoning from SO2. 3) The active-desorbing conducted by hot air blow-throw an AC is effective for C2H5OH, CH2Cl2 desorbing. We discuss the fundamental test and design conditions for TCCA.

In port injection, it is difficult to control in-cylinder fuel supply of each cycle in a transient state as cold start (in this paper, cold start is defined as several cycles from cranking at low engine temperature). Hence, THC, which is one of regulated emission gases, is likely to increase at cold start. As one of THC emission reduction approaches at cold start, the optimization of fuel injection specifications (including injection position and spray diameter) is expected to reduce THC emission. Setting injection position as downstream position is expected to secure the in-cylinder fuel supply amount at cold start because of small fuel adhesion amount on an intake port wall and a short distance between the injection position and in-cylinder. The position injection contributes to reduction of THC emission due to elimination of misfire.

In this paper, it is also elucidated that the influence of the downstream injection, which caused different fuel behavior in contrast with upstream injection, on the THC after warm-up and at the maximum power, as well as its mechanism. The mechanism is clarified by use of the intake port visualization system. First, at each injection position, the effect of injection timing on THC emission after warm-up was evaluated. In the downstream injection, THC emission increases during the injection timing, in which the fuel spray directly flows in-cylinder during the intake process (hereinafter defined as the intake valve opening injection timing), and the amount of THC emission is reduced at the other injection timing (hereinafter defined as the intake valve closing injection timing). Based on the results of visualizing the intake port, injected fuel phase near the intake valve is spray in the downstream injection.

As a result of our researches into reduction of exhaust emissions for small utility two-stroke engines which are widely used for handheld equipment such as a brush cutter and a hedge trimmer, we here discuss how much exhaust emissions can be reduced with only minor modifications of an engine. For the purpose of reducing emissions, we evaluated the effects of exhaust timing retard and of enleanment of carburetor mixture on mass emissions using the existing 25cc two-stroke engine, which emits high levels of HC and CO, and substantially low levels of NOx. We attained great reduction of HC and CO. The power output, however, dropped and both the plug seat and the exhaust gas temperatures rose, which would detract the practicability of the engine. But we solved the problems by modifying the combustion chamber and the exhaust port shape, keeping the emissions reduced as mentioned above.

This paper describes results of the thermal-hydraulic performance experiment system (THYPES) of the two-phase flow loop thermal control system using the test rocket which can maintain a gravity level of 10-4G for about six minutes. Feasibility study of this system had been conducted for loading into a experiment module of test rocket TR-IA No. 3. In 1991, engineering model of the experiment system was designed and manufactured in order to investigate its function, performance, and endurance against launching conditions. In 1992, flight model of the experiment system was designed and manufactured. The following tests were conducted so as to ensure the capability and compatibility of THYPES; functional test, performance test, environmental test, and interface tests between the experiment system and rocket avionics section. The experiment was performed on September 17, 1993 and the results are evolved.

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.

We developed active control more suitable for sports riding than the previous electronic stability control system for enjoying sports riding by many users. One of them, the traction control system S-KTRC (Sports Kawasaki TRaction Control) uses the sensor output like not only the slippage calculated from the front and rear wheel speed but also engine speed, throttle position, and gear position etc. As the result, conditions of the motorcycle and rider's intention are calculated by ‘Motorcycle model’ in the ECU continuously. By this ‘Motorcycle model’, S-KTRC confirms the real time conditions and predicts the succeeded condition, every 5milliseconds to decide to govern torque. The ABS system KIBS (Kawasaki Intelligent anti-lock Brake System), it is possible to control the rear wheel's lift by using the pressure data of the front brake at the sudden braking operation.

It is thought that the synthetic gas, including hydrogen and carbon monoxide, has a potential to be an alternative fuel for internal combustion engines, because a heating value of the synthetic gas is higher than one of hydrogen or natural gas. A purpose of this study is to acquire stable auto-ignition and combustion of the synthetic gas which is supposed to be applied into a direct-injection compression ignition engine. In this study, the effects of ambient gas temperatures and oxygen concentrations on auto-ignition characteristics of the synthetic gas with changing percentage of hydrogen (H2) or carbon monoxide (CO) concentrations in the synthetic gas. An electronically-controlled, hydraulically-actuated gas injector was used to control a precise injection timing and period of gaseous fuels, and the experiments were conducted in an optically accessible, constant-volume combustion chamber under simulated quiescent diesel engine conditions.

The feasibility study of the thermal control system for medium size or large size satellites was conducted to investigate the capabilities and specifications of devices such as cold plates, a radiator, a mechanical pump, and so on. In the first step of the system development demonstration, the cold plate was selected to investigate the performance among these devices. In this paper, the system concept of the advanced single-phase fluid loop and the evaluation by numerical analysis and experiments are described.

In the closed environments such as manned space station, it is necessary to remove contaminant gas to keep a suitable environment. Removal of gaseous contaminants generated from crew, animals, and plants is important function to keep the environment below the allowable level in the Closed Ecology Experiment Facilities (abbreviated as CEEF). CEEF consist of three modules for habitat, animal and plant, the supporting facilities for each module and a plant cultivation facility. CEEF are scheduled to be constructed from 1994 in Aomori Prefecture, northern part of Japan. For designing Trace Contaminant Control Assembly (TCCA) for CEEF, the following six (6) trace contaminants have been selected as major contaminant gas in CEEF; Ammonia (NH3) Methane (CH4) Ethylene (C2H4) Carbon Monoxide (CO) Nitrogen Dioxide (NO2) Sulfur Dioxide (SO2) Ethylene is well-known as an aggressive contaminant to plant growth and maturity.

A Temperature and Humidity Control (THC) assembly an essential system in order to provide comfortable environment for crew members in Japanese Experiment Module (JEM). Development of an engineering model (EM) and a proto model (PM) of JEM THC assembly started from March 1991 and completed on March 1995 successfully. In this development phase, it is called JEM EM phase, qualification test of THC was conducted to verify the THC design. This paper presents JEM THC design and an outline of the assembly model development.