Papers by Keyword: Slot

Abstract: At this time, it has become commonplace for aircraft to use high lift devices. The high lift devices used include flaps, slats, slots, elevators, ailerons, and others. This study examines the effect of multiple elements on the wing, especially the combination of slat slots and flaps in several configurations.. This research was conducted with numerical simulations on wing airfoil NACA 43018. The observed conditions were rectangular wing (no slats, slots, and flaps) compared to the use of slats, slots, and flaps under steady flight conditions. The angles of attack used are (α) = 0^o, 2^o, 4^o, 6^o, 8^o, 10^o,12^o,15^o, 16^o,17^o,19^o, and 20^o. Numerical simulation using Ansys 19.1 application with turbulent model k-ε realizable. The use of slats, slots, and flaps does not result in a shift in the stall point but tends to increase aerodynamic performance (C_L/C_D)which is very significant. By paying attention to pressure drag, viscous drag and the resulting induced drag, the use of slats, slots, and flaps reduces a large amount of induced drag so that the lift to drag ratio increases.

Abstract: Despite the numerous theoretical and experimental studies carried out throughout the years, the use of the Coanda effect in the propulsion-related field definitely remains one of the most current discussion topics since no definite conclusion has been drawn yet regarding the capabilities, applications and performances of the devices based on the Coanda effect. The present paper sets out to present the theoretical quantitative and qualitative aspects of the most important uses of the Coanda phenomenon, including the author’s own interpretations and ideas.

Abstract: In order to analyze the possibility of the fractional-slot concentrated-winding for wind generation, this paper states the merits of fractional-slot concentrated-winding permanent magnet machines, and then analyzes the electromagnetic design rules of fractional-slot concentrated-winding. The fractional-slot concentrated-winding permanent magnet machine is modeled and designed in electromagnetic, and its performance is analyzed, some conclusions can be obtained, which will provide reference for further analysis and application of fractional-slot concentrated-winding PM machine.

Abstract: This paper presents the design of a 2 x 2 microstrip array antenna suitable for wireless applications. Its basic structure is a microstrip comprising of three layers of which a 2x2 patches are etched on the top layer to act as the radiating element. The middle layer is a metal ground with rectangular slots and the bottom layer consists of a microstrip feedline. A larger bandwidth and the desired resonant frequency are achieved because of a reduction in the quality factor (Q) of the patch resonator, which is due to less energy being stored beneath the patch due to the rectangular arrangement of the slots. The characterization results of return loss, gain, and radiation pattern are presented consecutively. From the results, the simulated impedance bandwidth defined for S11<-10dB reaches 1850MHz (4.69-6.54GHz) representing 16.47%.

Abstract: Regarding the scheduling problem for real-time business over Bluetooth sensor networks, an adaptive scheduling algorithm for real-time business over Bluetooth sensor networks was proposed. By evaluating the current channel quality and data arrival rate, the best scheduling interval was computed for each link with real-time business. Master maintained a slot counter for each link and determined whether to schedule this link by comparing if the value of slot counter reached the best scheduling interval. The simulation results indicate that this algorithm has better bandwidth utilization, higher fairness and lower scheduling delay than traditional scheduling algorithms.

Abstract: Based on the analysis of features and NC-machining process of typical slots,a rule for slot-defining is given.An algorithm for toolpaths’ generation is proposed in the paper,via automatically obtaining the driving information of slot features.On these basis,under the environment of VS2010,a feature-based NC-processing system aimed at slots is developed,by which NC program can be made automaticly.At last,a simulate-actual processing test is done.The result shows that the algorithm proposed is correct.

Abstract: Through the analysis of the research status and application characteristics of the pipeline robot, a design of pipeline and slot multi-function robot is presented. The robot adopts pneumatic power systems and peristaltic walk way. The robot can move not only in reducing pipe to clean or detect, but also between the slot to rescue or transfer goods according to computer instructions. The system is operated by slave control unit and controlled by PC through an auxiliary rope, so the robot has advantages about real-time detection of the work state, strong driving force, easy maintenance and fault recovery, low cost and so on.

Abstract: Against some problems which exist in the current embedded graphical user interface development such as low efficiency in the operating, poor portability and so on. This paper brings up an embedded GUI development method based on Qt/Embedded. Firstly, the construction technology of X11 virtual compiler platform and the implementation technology of cross-compile environment are described in details which are necessary in GUI development. Secondly, the Qt library file is cut, and the picture is displayed with Chinese-characters in accordance with the specific embedded goal. In the end, prove the valid of the development method based on Qt/Embedded through applications.

Abstract: Electromagnetic compatibility is achieved by reducing the interference below the level that disrupts the proper operation of the electronic system or subsystem. This compatibility is generally accomplished by means of electronic filters, and component or equipment shielding. Shielding an electromagnetic field is a complex and sometimes formidable task. The reasons are many, since the effectiveness of any strategy or technique aimed at the reduction of the electromagnetic field levels in a prescribed region depends largely upon the source (s) characteristics, the shield topology, and materials. In this paper, the effect of an incident plane wave with linear polarization on aluminum shield in UHF frequency is investigated, then, the type of shield material is changed and shielding effectiveness caused by it is investigated. Also, the linear polarization of incident wave is converted to circular polarization and shielding effectiveness variation is obtained in this stage. Slots and apertures are very important parameters to determine suitable shielding effectiveness. In following paper, slot is placed on shield, and its shielding effectiveness is evaluated. The effects of slot width variation, slot length variation and slot displacement, on shielding effectiveness are investigated. Finally, the effect of different aperture structure is evaluated and shielding factor is obtained in any stage. The whole of simulations in this paper, are done with CADFEKO.

Abstract: The design of mechanical structures depends upon characterizing the stress/strain state in these devices under the combined influence of both loading and residual stresses. The performance of the dynamic structures is strongly influenced by residual stresses. Understanding of the behavior of gyroscopes in presence of residual stresses and ability to relieve the stresses are essential for improving the performance. In this paper, we briefly analyze the cause of residual stresses. The effect of residual stresses on natural frequencies of the drive mode and sense mode is theoretically analyzed. The FE model of the z-axis gyroscope is built to investigate the relation between the frequencies and the residual stress by model analysis. Methods for residual stress relief are presented. The results of the simulation demonstrate that the performance of the gyroscopes with serpentine beams and stress relief slots can be improved significantly.