Advanced Materials Research Vols. 1079-1080

Abstract: Exhaust passage is a significant part of the gasoline engine, its structure will affects the gas flow characteristics of the engine directly [1]. So, research and analysis of the exhaust tract is essential. In this paper, a detailed analysis of the flow field under cold state and hot state was made. For a start, the method of laser scanning and UG software were used to reverse modeling engine exhaust port and get the three-dimensional model. The next, the unstructured grid with local mesh refinement scheme was used to mesh this three-dimensional model with ICEM. After this, numerical simulations of the exhaust passage with five different valve lifts were carried out under thermal and cold conditions. Finally, comparing the velocity field and pressure field of the exhaust passage under cold state and thermal state, it can be find that the flow field under hot and cold state have similar characteristics. The results of this paper can provide a theoretical basis for following researches of the engine exhaust port.

Abstract: Aimingto improve the shortcomings of the AMD control system, new direct drivingactive mass driver (DAMD) is developed.The mathematical models of hydraulic power mechanismand hydraulic actuator of DAMD are set up, which leads to the whole equation ofrotation speed-drive force is constructed and the rotational speed of the pump(the driving voltage of servo motor) as input and the active control force asoutput is used. From the above derivation and analysis, the state equation forcontroller structure-DAMD control system is presented. Numerical analysis iscarried out on the structure responding control of the DAMD control system structurewhich is a top designed study object under earthquake load action. Results showthat in some degree,DAMD control system can be used to substitute thetraditional AMD control system for large-span structure to realized activecontrol of structural vibration.

Abstract: Intake port is an important part of the gasoline engine, its structure will influence the gas flow characteristics which directly affects the performance of the engine [1]. In this paper, three-dimensional CFD calculation and structural optimization were used to research the performance of gasoline engine. Firstly, the method of laser scanning and UG software were used to reverse modeling engine exhaust port and get the three-dimensional model. Secondly, after setting boundary conditions and turbulence models, the air flowing through the intake ports were simulated by FLUENT software respectively. Finally, based on numerical methods, the pressure field, velocity field were shown. The results of the simulation of flow field characteristics analysis show that the simulation and experimental results are in good agreement.

Abstract: The performance of the engine air intake system directly affect the working performance and fuel consumption, where the intake manifold design is the key.In this paper aimed at L91 Engine intake manifold ,firstly theRE(Reverse Engineering)technology was usedto rebuild the3d model of intake manifold.And then the internal flow zoneof the intake manifoldwas meshedin the pre-processing software ICEMand the internal flow fieldwas analyzedin the softwareof Fluent.The numerical model was verified by comparing the simulated and measured results. And then based on the numerical analysis of the internal flow characteristics of the intake manifold, the structure of variable-length intake manifold was come up with and finally was numerically proved to be better than the normal one.

Abstract: Thispaper designs a set of experiment system for stepper motor, the control system ofstepping motor is composed of stepper controller, drive and stepper motor, withthe single chip processor as the stepper motor controller to realize the morecomplex stepper motor control function. This system has got good teachingeffect in experiment teaching.

Abstract: In order to demonstrate the synchronous driving capability of multi-servo motor, an improved synchronous drive control platform based on DSP used in teaching was established. The dedicated motor control chip ASIC-TMS320F2812A was adopted with a unique independent PWM control signal output function. The hardware components were introduced, resulting in principle and duty cycle of the PWM waveform calculation. The tests showed that the DSP servo control system has good performance of high reliability, fast dynamic response and low noise.

Abstract: It’s very important for the traffic flow theory, the traffic management and control, and the programming and design of roads to master the law of speed. And the most intuitive form is the speed distribution to describe the law. Based on the maximum entropy principle, this paper proposes a model which can generate the speed distribution curves only with the observed date. And the availability of this method has been proved by the example analysis. The fact has also been found that fitting with maximum entropy distribution is better than with normal distribution in peak hour and is worse than it in off peak hour, but the difference is not great. This model does not need assumptions. Moreover it has a simple calculation and a strong practicability. So this paper makes a contribution to the study of the speed distribution.

Abstract: This paper presents an innovative design of pneumatic exhaust devices,in order to solve the problems of excessive weight and slow movement of traditionalelectric exhaust devices. The research method was TRIZ. The inventionprinciples for systematic innovative design were identified by using improvedand worsened parameters of the contradiction matrix. The pneumatic exhaustdevice was 5 kg, and operated for 30 minutes at 1800RPM per 10kg of air amount.Its purpose was used to rescue persons trapped by dense smoke within shorttime. The proposed invention can be applied to dense-smoke place wherecombustible gas may leak, because the traditional electric exhaust devicesgenerate spark during operation which may cause gas explosion. Moreover, theproposed design uses pneumatic exhaust devices, which are especially used inplaces where gas explosion may occur, and has the advantages of flexibility, safety,and portability. The proposed design is an excellent fire protection device,and can be used to rescue persons trapped by dense smoke and fire within shorttime.

Abstract: This study proposed an innovative design of pressuresensing pacifier to solve the problem of lack of sucking ability of newborninfants or premature infants, as well as the problem of caregivers lacking inthe knowledge of when to feed the infants. TRIZ was adopted as the researchmethod. The modification and deterioration parameters of contradiction matrixwere used to identify the invention principles for systematic innovationdesign. Moreover, the seven techniques of the universal design were used toapply the proposed pressure sensing pacifier on infants. The pressure of thepressure sensing pacifier was in the range from -50 to -75mmHg. Bymodifications of these data, the infants are allowed to receive better care.This study also designed a set of pressure sensing device for clinical medicalpersonnel and researchers to measure the sucking ability of premature infants.The objective assessment tool is expected to help medical personnel to masterthe development stage of the sucking ability of premature infants to identifythe best feeding opportunity.

Abstract: With the deepening of reform in the industrial sector, automotive manufacturing technology has been greatly improved. Suspension damping effect of the traditional shortcomings of poor correlation analysis suspension constituted by employees, starting from the improved shock absorber damping valve, designed and developed Nepal adjustable shock absorber set, in order to improve traffic safety and create favorable conditions. This damper is in the computing speed and power, the analysis of the relationship between the motor and the throttle on the invention came. Practice has proved that through adjustable automobile shock absorber damping curve smoothing, deformation is not obvious, the stepper motor rotation into correspondence with the damping force, with better value.