Advanced Materials Research Vol. 1078

Abstract: The jet noise reduction of chevron nozzles was investigated on high bypass ratio turbofan engine separated exhaust system using both computational predictions and scale model experiments. Six different exhaust nozzles are designed including one baseline nozzle and five different chevron nozzles. The jet noise experiments were carried out in the anechoic chamber. Tam and Auriault’s jet noise prediction theory and MGBK theory were used to predict the noise spectra of different exhaust nozzles. The results show that the far-field noise spectra as well as the noise reduction benefits of chevrons are predicted correctly by the two theories although some discrepancies occur at the high frequency range, and Tam and Auriault’s jet noise theory can give relatively more accurate prediction results. chevron nozzles reduce jet noise at the low frequencies, but increase it at high frequencies.

Abstract: Abstract. Modular modeling method was adopted to build model for the engine’s electronic control system , including the engine system model, sensor model, controller model and actuator models. For the engine system, the modeling approach of the average value was used to establish an air supply system model, the fuel supply system model and the engine power take-off model. By the method of mathematical fit, a mathematical model of electronic control engine’s sensors was established. Based on Mat-lab/Simulink, it designed simulation system and proceeded simulation tests for each model of engine control system, then the results show that the model is correct, and it can manifest the changes of relevant parameters during the actual operational process of the engine.

Abstract: Tuyere raceway was known as the "engine" of the blast furnace, which plays a very important role, but it is very difficult to be directly measured and researched, because of limitation of experimental methods. In this paper application of kinetic theory of granular flow,coke particles as a pseudo-fluid, the two-phase raceway model of gas-solid was constructed by used of Eulerian two-fluid theory, and the model was verified correct.

Abstract: Signal of ultra high sensitive detection has important application value in the fields of electrical engineering. In recent years there has been a distributed feedback (DFB) fiber laser is a new generation of optical fiber sensing elements of the sensor. It has small size, spectral line width output laser signal is very narrow and low noise advantages, the detection sensitivity can reach high combined with high resolution wavelength demodulation technology. This paper introduces the fiber laser sensor technology and its progress in research and application of technology of detecting signal.

Abstract: The hash function is the acceptance of variable length data input, and generating function of fixed length data output. Message integrity requirements of any changes to the received data can be found, and main function of hash function is to realize the integrity of data security. The hash function is very suitable for certification and ensures data integrity. This paper firstly analyzes the working principle and performance of the improved hash function. The paper proposes application of improved Hash function in the message authentication and message integrity.

Abstract: Smart sensor has the following three advantages: realize the information acquisition of high precision and low cost, it relates to the micro mechanical and microelectronic, signal processing and computer technology. The purpose of data mining is to discover knowledge. Knowledge of association rules mining aims to find out the related information hidden in the database. The paper presents application analysis of smart sensor node based on data mining association technology. Experimental results show the proposed methodology has advantages in the management of the intelligent node.

Abstract: The execution of the PLC application is accomplished through hardware, while the PAC designed a generic form of software execution cores for executing user application execution cores located between the real-time operating systems and applications, the implementation of the kernel and device hardware platform independent, this paper presents under the PLC and PC continuous development and integration of the case, its organizational structure with high computing and large storage space advantages of a PC with high stability.

Abstract: In this paper, GPRS module, including the design and implementation of the telephone terminal interface circuit design TV interface circuit, interface GPRS module and starting circuit are designed based on ARM embedded platform. Software is also designed primarily Bootloader and Linux kernel porting, system part of the driver, the results of the design through experimental verification, the results show that the system can communicate data, you can use AT commands to achieve messaging and voice capabilities.

Abstract: This paper establishes the finite element model of reachstacker spreader, makes static strength calculation under eight typical operating conditions with rated load, based on the calculation results, it points out the weaknesses of spreader and gives some corresponding improvement measures for the drawbacks. Further analysis shows that the maximum stress of improved spreader mechanism has reduced 10.1%, which demonstrates the effectiveness of improvements.

Abstract: Experimental study on macroscopic spray characteristics of a certain type of domestic common rail injectors under the conditions of different injection pressures was carried out through a high-speed digital camera. Furthermore, a fuel dripping phenomenon at the end stage of injection was observed through the high-speed digital camera equipped with a long-distance microscope, and a further analysis of the phenomenon was made. The results show the increase in the injection pressure can evidently enhance spray cone angle and expand the scope of spray field in combustion chamber, which is conducive to air-fuel mixture. The spray cone angle during the development spray shows a double-peak shape. And the long response-time of seating of solenoid valve core that disables the injection cutting off in time is one of factors causing fuel dripping phenomenon.