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A reciprocating compressor is commonly used in industry. However, because it is extremely noisy and harmful to the ears, a noise control mechanism is necessary. Eight kinds of noise control strategies used with the reciprocating compressor are explored, and COMSOL, a numerical analysis software, is adopted for acoustical analysis in the paper. The primary purpose of this research is to assess the influence of seven noise control strategies for the suction/discharge muffler of a reciprocating compressor. Results have shown that the noise control strategies can efficiently improve the acoustical performance of the suction/discharge mufflers. [ABSTRACT FROM AUTHOR]

Presently, there is a trend to design larger capacity hard disks that have a faster revolving speed and a precise mechanism. However, because of external vibrations, these are highly sensitive to data transmission. Therefore, vibration control on hard disks is crucially important. In this paper, a traditional hard disk is placed on a vibration testing device. Data transmission efficiency for the disk will be detected via IOmeter software. Here, the influence of a traditional hard disk's data transmission with respect to external forces (various vibration accelerations), revolving speeds, tilted angles, hardness and thickness of damping material, and material property will be experimentally assessed. Results reveal that a slight tilted angle will result in better data transmission. In addition, the hardness of the hard disk plays an essential role in reducing the vibrational impact on the data transmission. Also, data transmission in the damping material of the shoe cushion will be more efficient than that of a pneumatic cushion. Moreover, the data transmission will decrease when the rotating speed of the disk increases. Consequently, the thickness of the damping material will influence the data transmission even though the hardness is fixed. [ABSTRACT FROM AUTHOR]

To increase manufacturing productivity, industrial automation is required. Additionally, in order to monitor the manufacturing process, a remote online monitoring and control system becomes compulsory. A conventional remote monitoring system often uses a wire connection for communication within a control center; however, it is time-consuming and inconvenient. To overcome this drawback, a wireless design is proposed for the manufacturing process. In this paper, a case study of a remote wireless monitoring network used in a shape judgment system is introduced. In order to connect the server pc and the PLC (a controller of a shape judgment system), a ZigBee wireless module in conjunction with a transparent mode is used. Additionally, the interface of the above system is established with a Visual Basic 6.0. One of the advantages in using a wireless network to connect with a server pc and a shape judgment system is that the server pc is movable. Moreover, the remote monitoring function at the client pc can also be utilized using a TCP/IP protocol. Consequently, a prototype of a wireless network and a remote control for a shape judgment system using a ZigBee module that reduces the cost in electrical power and saves time in the system's installation is exemplified. [ABSTRACT FROM AUTHOR]

To simplify the optimization process, a simplified mathematical model of a muffler is constructed using a neural network and a series of input design data (muffler dimensions) and output data (theoretical sound transmission loss) that are obtained by utilizing a theoretical mathematical model (TMM). To assess an optimal muffler, a neural network model (NNM) is used as the objective function in conjunction with a genetic algorithm (GA). Before the GA operation can be carried out, however, the accuracy of the TMM must be checked and be in accord with the experimental data. Additionally, the NNM must also be in agreement with the TMM. Also discussed are the numerical cases of sound elimination relative to the various parameter sets and pure tones (500, 1000, and 2000 Hz). The results reveal that the maximum value of the sound transmission loss (STL) can be accurately obtained at the desired frequencies. Consequently, the algorithm proposed in this study can provide an efficient way to develop optimal silencers for the requisite industries. [ABSTRACT FROM AUTHOR]

As investigated by the Occupational Safety and Health Act (OSHA) in 1970, noise is highly responsible for the psychological and physiological illnesses of workers. Therefore, noise control for an enclosed manufacturing system using sound absorbers becomes indispensable. Considering the minimal acoustic wool used in the high-performance sound absorber during design optimization, the ratio of the sound absorption coefficient to the thickness of acoustic wool, a cost- and performance-oriented design index, is then applied and served as a researched objective accordingly; what’s more, the thickness of the absorber is fixed in advance for the sake of maintenance and access. In this paper, not only is the graphic analysis studied, but also, the computer-aided numerical assessments are presented. In the computer-graphic analysis on sensitivity, one set of design data is developed first. Additionally, the successive algorithm of iteration techniques and the original design data are carried out independently. Moreover, the results are then confirmed by the Kuhn-Tucker condition for accuracy purposes. It is shown that the theoretical and simulated results are in good agreement. The economical design of the sound absorber proposed in this study definitely provides a quick and optimal approach to minimize the amount of acoustic wool used and retain the higher acoustic performance of perforated single-layer absorbers under space restrictions. [ABSTRACT FROM AUTHOR]

Whilst the space volume of mufflers in a noise control system is often constrained for maintenance and operation in practical engineering work, the maximization of the muffler's performance becomes essential. In this paper, both simulated annealing (SA) and a genetic algorithm (GA) are applied simultaneously. A numerical case of pure tone noise control is introduced. Before optimization, one example is tested and compared with the experimental data for the accuracy check of the mathematical model. The results reveal that the GA is more accurate than SA during the optimal process with a fixed iteration. Under space constraints, this approach provides a quick and novel scheme for the design of double-chamber mufflers. [ABSTRACT FROM AUTHOR]