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The electronically controlled shock absorber with magneto-rheological fluid, KF-MRS07, was developed for the Formula SAE (FSAE), which is an annual collegiate racing competition. The KF-MRS07 has been newly developed based on KF-NS06, a mono-tube type shock absorber produced in 2006 incorporating commercial oil. The KF-NS06 is a low cost product but hard to adjust the damping property. On the other hand, the KF-MRS07 can be controlled electronically whose damping force is changeable instantaneously while running. The equivalent viscous damping coefficient, the measure for evaluating the shock absorbers, is changed about 99% with 1.0A applied current. On-track test results show that the yaw rates can be changed from an oversteer condition to an understeer one with a simple threshold control.

The simplified shift/clutch operation system, KF-TOS-P, was driven by DC motors (DC12V driven) with a microprocessor. Two rotary sensors detected the positions of the shift lever and the clutch lever. In FSAE rules, the simple throttle-by-wire is prohibited and the engine speed was controlled by the drivers. The custom steering wheel, KF-SW07 as the human machine interface, was designed and manufactured with CFRP by VaRTM (Vacuum assisted Resin Transfer Modeling) method. The shift operation time of KF-TOS-P was half of the manual operation and the clutch engagement time of that was 25msec. KF-SW07 was 22.6% weight and 16.7% cost (calculated by FSAE rules) of the commercial steering wheel of the race use.

The Traction Control Systems (TCS) for the FSAE car were developed with the Fuel/Ignition Cut (FIC) method and the Ignition Retard (IR) method. A slip speed was used for the TCSs and a custom Engine Control Unit (KF-ECU07) was developed with commercial devices. With the FIC TCS, the engine was stalled and the IR TCS worked better. KF-ECU07 was 7.6% of the commercial high-quality ECU in price and contributed to the cost event point gain in FSAE. The driver load was evaluated with the duration ratio of the partial throttle aperture. The duration ratio of the partial throttle aperture was 52% with the IR-TCS compared with 64% without IR-TCS and 19% driver load was decreased.

The Formula SAE (FSAE) rules require mounting an impact attenuator (IA) to the front part of the formula car. The IA is necessary to take fully into account not only lighter weight of the parts but also cost effectiveness as the total cost and the workability of manufacturing have much value to win the FSAE. In this paper, three different IAs, 1) a space frame structure with steel pipes (SSF), 2) a monocoque structure with aluminum (AM) and 3) a monocoque structure with Carbon Fiber Reinforced Plastic (CFRPM), were manufactured and compared with respect to the weight and the cost effectiveness under FSAE rules. The FEM simulations for the AM were performed and the calculated results showed good agreements with the experimental ones. However, the AM could not absorb the impact energy experimentally. The CFRPM could absorb the required impact energy with lighter structure compared to other IAs. The weight was half of the experimental SSF and 1/5 of the calculated AM.

The turbocharged 4-stroke internal combustion engine was developed for FSAE, the annual collegiate racing competition. The dry sump lubricant system with the custom scavenge pump, KF-SC07, was designed. The crank axle height was 192mm, 76.5% of KF2004. Custom cam-shafts were designed making the torque fluctuation decreased less than 50% of KF2005. The compression ratio was changed. And the maximum boost pressure and the maximum torque gain were 25kPa (0.25 kgf/cm2) and 11%, respectively.

The ideal torque curve of automotive engines should be high and flat from low engine speed. To achieve this, we installed a variable nozzle turbine (VNT) turbocharger to a retail natural aspirated (NA) small gasoline engine. In the VNT turbocharger, variable vanes are set around the turbine wheel and form nozzles that changed the flow velocity of the exhaust gas. The vane position was controlled to adjust intake pressure at a target. As a result, the maximum torque improved by 27% and the engine speed at maximum torque was lowered by 1550rpm. A flat torque curve was achieved from 5450rpm to 8000rpm.

This study proposes a method of decreasing the engine idle speed for the engine of FSAE race car. In general, the engine is controlled by map-based method. However, this method requires much time and cost to create a fuel injection map and an ignition timing map [1]. In addition to this, creating these maps at idle speed is much harder because the engine speed is cranky at idling. In this study, ON/OFF control and PID control were used for idle speed control without creating maps. As a result, idle speed was decreased drastically compared with map-based control. The PID control was able to stabilize the idling compared with the ON/OFF control.

A microwave-heating system is integrated in a port-injector to minimize the cold-start problems and exhaust emissions of engine. This paper report the experimental investigations of spray characteristics and numerical simulation of fuel temperature inside port-injector. Fuel flow inside port-injector is heated using microwave-heating and this system is called “local-contact microwave-heating injector” (LMI). LMI can be used to increase temperature of ethanol near boiling point (351.5K) before injected into room temperature. Injection pressure of fuel was operated constant at 0.3MPa. Characteristics of fuel spray were observed experimentally using high speed camera, CMOS camera and LDSA. Numerical simulation was conducted to verify the effect of local heating on spray distribution. 2-D geometry of injector with finer quadrilateral mesh (56,000 meshes) was solved numerically on pressure based solver in CFD simulation code.

Cylinder pressure is used for the closed-loop ignition angle control of a gasoline engine. This paper focused on the crank angle position where the maximum cylinder pressure reached (θPmax) and the relationship between the θPmax and the ignition angle. This closed-loop control set the θPmax a target value with an initial ignition angle and does not need a detailed ignition angle map. Response time and deflection with the target value are examined with a test bench. The θPmax target, ATDC 18 deg. is confirmed in consideration of the effect of knocking and the exhaust gas composition. The target ignition angle was varied step by step within a limit of upper and lower values, the response was observed and each gain was decided. At the engine speed of 5000 rpm, the duration to reach a steady value of θPmax is 0.10 s and the response time of ignition angle is 0.02 s.

Chassis performance greatly influences driving in the turn inn movement. Spec of the active damper is simulated to achieve a chassis that satisfies various requirements. In this paper, an MR-damper (Magneto-Rheological fluid damper), which is high-response active damper, is chosen. The MR-damper is mounted in FSAE vehicles and controlled vehicle behavior electronically in a simulator. As a result, the MR-damper brought a big effect to pitch action rather than roll action, and an initial damping force effected vehicle behavior more than damping force change ratio.

Improvement of atomization process is one of the most effective methods to promote the cold-start period of an internal combustion engine (ICE) using port fuel injector (PFI). In this paper authors present a fuel heating method using microwave energy through the local-contact microwave-heating injector (LMI) to enhance the properties of fuel sprays in such a risky working area of ICE. Temperature and mixing ratios of blended fuel are varied and characteristics of atomization are investigated. The fuel using in experiments is blended fuel of gasoline and ethanol, the mixing ratio is varied among 0 (E0), 5 (E5), 50 (E50), and 100 (E100) percentages in volume ratio of ethanol. The temperature of the fuel is measured just before the injection by using K-typed sheath thermo-couple. Spray characteristics measured are Sauter Mean Diameter (SMD), droplet size distribution, spray cone angle, and particle size distribution width.

This paper investigates influences of intake and exhaust valves overlap (at this duration, both of the intake valve and exhaust valve are open) on engine performance. An electric, variable cam phase mechanism (VVT, Variable Valve Timing unit) is installed in a small gasoline engine. The influences on the engine torque and BSFC, Brake Specific Fuel Consumption, are investigated on the engine bench. In addition, in case the overlaps exceeding the experimental range an engine simulator is used to predict the effects. The experimental results indicate that the VVT system can adjust the target overlap with the accuracy of 1.5deg. in a range of engine speed from 3000rpm to 7000rpm. The response time of the VVT unit was observed at the engine speed of 3000rpm. The results show that the rotation direction of motor affects on the response time of the unit. The measurement of engine torque and BSFC is performed for several overlap values at each engine speed.

MR-damper (Magneto-Rheological fluid damper) is used an actuator with high speed in response to control the movement of four-wheel vehicles. In this paper, performances of two MR-dampers were measured. These dampers had difference in diameter of cylinder, length of piston and orifice. These changes will influence the damping force, the damping force change ratio and the response time of damping force change. As a result, a larger damper showed 1.4 times damping force change ratio of smaller one and shorter response time in compression.

In emergency, it is not easy to get enough fuel for generator and the usage of kerosene with small spark ignition engine for normal gasoline was investigated. As too much kerosene will cause knock, EGR (exhaust gas recirculation) system was used to reduce the knock strength. The displacement was 290cc and the compression ratio was 8.4. The knock strength was evaluated with a highpass-filtered strain sensor and 0.6V was measured at MBT (Minimum advance for Best Torque) with normal gasoline, 1800rpm, 10Nm. The engine speed was almost 1800±100rpm and the torque was almost 10±0.1Nm. As a result, the EGR system could reduce the knock strength in any kerosene mixture fuel with the control of the ignition timing.

An experimental study has been conducted at small kerosene droplet behavior near well-defined butane diffusion flame for the critical need on high efficient and cleaner energy technology. High temperature of background gas was generated using butane flame. Microflame from butane can reach the maximum temperature around 1200K at tip of outer glass. Single droplet of kerosene was injected by a small injector tube (30 μm-diameter) in to hot environment. Droplet of kerosene was released by attachment of piezo actuator on wall injector. Once the droplet is exposed to the hot atmosphere of micro flame, the temporal regression of the droplet surface was recorded. Droplet diameter was observed by CCD camera with strobe light flash at 180ns. The images captured in this experiment were analyzed by post-processing software to determine the vaporization of droplet.

Small wood biomass gasifier was developed and co-generation system supplying electric power and heat with small spark ignition internal combustion engine (SI-ICE) was investigated. The balance of electric power and heat flux will be controlled with ignition timing and the exhaust gas components were discussed. The wood biomass gasifier (downdraft type) had 105mm in inner diameter and 1000mm in length and the reaction zone temperature was 900deg-C at 68NL/min in intake air flow. The SI-ICE had 290cc in displacement and 8.4 in compression ratio and was driven at 1500rpm. The ignition angle was changed from 30deg-BTDC to 25deg-BTDC with almost same exhaust gas components. The exhaust gas temperature was from 520deg-C to 555deg-C.

In this study, the background gas of the droplet vaporization was concerned and simulated numerically using ANSYS fluent code. The new type, engine-like, condition of high pressure chamber and high temperature environment was considered to conduct experiment on kerosene droplet evaporation. 2D geometry of domain simulation was discretized in the very fine quadrilateral meshes. The numerical approach was solved using implicit scheme of compressible gas solver (density based). Temperature dependent properties of air are expressed for gas material properties. As the study concerning on high pressure condition the equation state of Peng-Robinson was expressed in simulation. Governing equations of mass, momentum and energy were solved by the second order upwind for flow, turbulent kinetic energy and turbulent dissipation rate. Standard k-ε model was used to solve turbulence flow in the spatial discretization.

In this paper, droplet behavior near diffusion flame was observed. Single droplet was created by thin glass tube and piezo device which pushes the side of glass tube. Dispersions of droplets location near diffusive flame were compared to droplets with no flame condition. CCD camera, strobe light with 180nsec flash time and lens of ten magnification were used for observation. Droplet pictures were taken with resolution of 0.46um/pix. As a result, droplets near diffusive flame tend to increase its dispersion of location as approaching tip of the flame. Stefan flow caused by evaporation and turbulence outer flow can be thought as causes.

In internal combustion engine, it is necessary to grasp droplet evaporation for using liquid fuel efficiency and improving exhaust gas composition. However, it has not known completely yet. In this study, fuel droplet of approximately 20μm diameter that is assumed to be in combustion chamber is injected by experimental apparatus. After that, droplet goes to butane flame. We observed by high-speed camera, and experimentally considered the effects of heat flux on the fuel droplet evaporation and breakup phenomenon. For the sample fuel, we use kerosene and diesel oil. It is important for understanding evaporation condition to know temperature around droplet in butane flame. Thus, flame temperature is measured by sheathed thermocouple. Heat flux is changed by initial velocity. From experiment, we found some result. Time that from injector tube to location of breakup of the droplet is short by increasing heat flux.

Liquid fossil fuels such as gasoline, diesel oil, and kerosene are widely used as a fuel of various transportation apparatus and generating electricity apparatuses including the automobiles. The spray combustion has been widely used for internal combustion engine to use the fuel efficiently. But some parts of the phenomenon are not elucidated because this combustion method is complicated phenomenon. To elucidate this phenomenon, there are many ways of analyzing droplet. For example, observing a single droplet which suspended by a catenary or under the microgravity. However, those methods are not enough simulation of a real droplet in the internal combustion engine. In this study, we developed an apparatus which could inject a freedom droplet of diameter about 30µm. It is considered that the droplet is in a real internal combustion engine. And the apparatus was installed in a container which could realize elevated temperature and pressure.