Xian Feng Huang

Prediction of the Sound Pressure Level in a Small Room

Two concise calculations of the sound pressure level (SPL) in a small space have been developed by establishing the prediction model. The models can be employed to predict the SPL accurately, which affects speech articulation in small space. So these methods may be able to evaluate the acoustical qualities of the chambers in a building. It is facilitate the further acoustical design in a room with small size.

Prediction on the Sound Insulation of a Double -Leaf Lightweight Panels

Statistical energy analysis (SEA) is utilized to model sound transmission through a double -leaf lightweight. Calculating the sound insulation by this method and comparing with the measured data have shown that the prediction model may generate a certain difference between the prediction and experimental data, this method, moreover, might further solve the problem of the sound insulation of the complex wall structure by optimizing the configuration of the enclosure structure.

Research on the Prediction of Impact Sound Insulation to a Homogeneous Wall

In this paper, a theoretical model to evaluate impact sound transmission through a homogeneous wall is proposed. The model which is based on the Statistical Energy Analysis framework exhibits a system with room-wall-room. For the purpose to explore the mechanism of impact sound transmission through a wall, the impact sound reduction index between two rooms are predicted. Meanwhile, the variation of impact sound reduction index with the walls properties are also taken into account. The results reveal that the density, elastic modulus and thickness of a homogeneous wall have diverse effects on its impact sound insulation and can be chosen adequately to achieve ideal insulation values.It provides an approach to optimize impact sound insulating properties of the walls.

Prediction on Coupling Loss Factors of Building Members

Coupling Loss Factor (CLF) is a parameter describing building sound loss, which can be stand for energy loss in the process of crossing the structure. A low value of CLF refers to the high insulation performance of building member. Therefore, reducing the coupling loss is a favorable way to improve the sound insulation. For the purpose of exploring the relationship between the properties of building materials and CLF, the commonly used building materials are selected to analyze. It is indicated that the properties of building material have obvious effects on the CLF. As the consequence, some predictions and analysis are carried out in this paper.

Slits' Effects on Sound Insulation for Lightweight Partitions

The slits on the lightweight partitions have a significant effect on sound insulation which is investigated in this paper. According to Gomperts model for rectangular aperture, the sound reduction index of a wall with slits can be predicted. Two lightweight partitions were selected to analyze their sound reduction index variation with factors such as width, length and location of slits. Results show that these factors affect the sound insulation evidently, especially at high frequencies.

Prediction on Modal Properties of Building Plates

Statistical energy analysis (SEA) method is an adequate tool to solve complex problems to building acoustics. This research on the application in variety of the building materials as the subsystem of SEA model is performed. For the purpose to explore the relationship between the building element and its mode, these commonly used building materials are selected to determine this relationship. It is indicated that the properties of building material have obvious effect on the modal density and modal overlap of building members. As the consequence, a useful technique to account for a building member to be appropriate for a SEA (statistical energy analysis) subsystem is presented.

Analysis on Traffic Noise Attenuation by Using Sound Barrier

By applying noise insertion loss predicting model of the noise barriers, influencing factors on insertion loss of the sound barrier are investigated for achieving the significant attenuation effects. In term of the infinite line sound source and the finite length of the barriers, the sound insertion losses with varying parameters are calculated and compared. Finally, the meaningful results indicate that the economic and reasonable height and length of the noise barrier are gained to be beneficial for barrier design.

Motion Control in a Free Piston Energy Converter Based on a Neural Adaptive PID Decoupling Controller

The free piston energy converter (FPEC) is a combination of a combustion engine and a linear electrical machine which develops a new type of power unit for hybrid electric vehicle. The movement component of the FPEC is a multi-input multi-output coupling nonlinear system. As a consequence, an adaptive decoupling control strategy is presented in this paper for controlling the piston motion. Two neural PID controllers in parallel are employed as the decoupling controller, in which PID gains are auto adjusted by supervised Hebbs learning rule. Simulation results show that the utilization of the neural adaptive PID decoupling controller gives rise to stabilize the piston motion.

Optimization to Human Thermal Comfort in Transitional Spaces by Artificial Immune Algorithm

The HVAC (Heating, Ventilation and Air-conditioner) technology is an efficient approach to achieve dynamic thermal comfort in the transitional spaces where connect the interior and exterior space. The paper describes an optimized method to thermal environmental parameters in the hot summer and warm winter zone is benefit to human comfort, health and energy saving. Based on the dynamic comfort equations and the advantage of artificial immune algorithm in tackling combinatorial optimization to engineering problems, the artificial immune algorithm has been applied to the optimization of thermal parameters for the HVAC design within a transitional space. Therefore, it is shown that the proposed algorithm here might be adopted in the control of the HVAC system.

Chaos Identification and Suppression in an Indirect Field-Oriented Control of Induction Motor Drive Based on 0-1 Method

A period-doubling bifurcation may occur when the estimation error of the rotor time constant exists in an indirect field-oriented control (IFOC) of induction motor drives. Then chaos oscillations appear under some parameter values which are usually tested by the Largest Lyapunov exponents. In this paper, we apply the modified 0-1 method to detect chaos phenomenon instead, and design a controller to suppress chaos in the IFOC system. Simulation results indicate that the proper parameter region of the controller can be obtained with this method, and with the adaptive controller the system can quit from the chaotic state into the stable state effectively and robustly. The 0-1 method identifies chaotic behaviors directly through the time series without constructing phase space. Therefore, the proposed method is not affected by the complexity of the system and is not sensitive to noises.