Advanced Materials Research Vol. 933

Abstract: Workflow is a key technology of process management and process control in PDM system. It introduce the definition of workflow and the workflow management model ,and define standard process of all kinds of documents management graphically and task nodes of different business process, which include design flow and drawings change process. It makes the manageability enhanced, and improve the automatization and the efficiency of flow execution, realize the workflow management in the design of drilling rig.

Abstract: In aircraft preliminary design, fuselage structure design is important, and to reach the lightest weight is the main target for aircraft design, especially for civil aircraft. Based on CAD/CAE technology, the paper selects a typical structure layout form of aircraft mid-fuselage to study the method of structure model quickly creation and optimization. First, it focuses on fuselage parameterized modeling method, based on CATIA secondary development technology, to create the mid-fuselage parametric model. Then, based on Patran command language, the CAD model achieves automatic meshing. Finally, selecting an appropriate strategy and using iSIGHT integrated with fuselage parametric model and finite element model, and referring to the calculated the structural response by Nastran to realize mid-fuselage structure optimization.

Abstract: It is well-known that reliability of equipment is the most important of all performance to all equipments. In order to make the equipments which include mechanical equipments, electrical equipments and so on work normally, reliability theory FMECA is applied in an aviation equipment to study its reliability and improve operational reliability of the product. Through its reliability mathematical model, average of operational time is predicted based on calculating failure probability of all electrical components. According to the process of FMECA, all kinds of the failure mode, reasons, effects and criticality of the products can be determined completely. By comparing these criticality data as shown, the paper analyses adopted method by that the contents, accents and operating process of maintenance may be instituted finally. FMECA-based method for reliability study of the equipment and the equipment maintenance perform well. The results indicate that application of FMECA method can analyze reliability in detail and improve operational reliability of the equipment. Therefore this will supply theoretical bases and concrete measures of maintenance of the products to improve operational reliability of products. FMECA can be feasible and effective for improving operational reliability of all equipments.

Abstract: A new downhole hydrocyclone desander with spiral deflector and cyclone cone was designed to apply in downhole solid-liquid separation according to the downhole operating conditions, such as a high produced liquid viscosity, narrow radial working space and closed bottom flow, etc. The structure parameters were designed primarily based on the effect of structure size on pressure drop, production capacity and separation efficiency. Numerical simulation was conducted on the base of Mixture model and Reynolds stress (RSM) turbulent model by Fluent CFD software. The geometrical model of single inlet and single outlet was established. The simulation calculations were carried out to analysis the effect of structure parameters change on separation efficiency and pressure drop, obtained the influence rules. The optimum structural parameters were confirmed. The numerical simulation results lay the foundation for the next experimental study.

Abstract: The contact ratio of noncircular gears is variational, much more complicated than the contact ratio of the spur gear. Because the contact ratio of straight noncircular gear is always less than 2, its property of steady transmission is less than the bevel noncircular gear. Withal the thesis exports the calculation method of the bevel noncircular gears contact ratio and its variation range,and gives the relative computing examples .

Abstract: In the present study, an airship for the fixed point observation of nara withering in village forests was designed and trial manufactured. The airship consists of a helium gas filling envelope of 4.5m in total length, propeller-driven motors, a polymer electrolyte fuel cell (PEFC) in order to achieve longer flight, Ni-H batteries, a CCD camera observation system, and propeller control systems. Automatic charging device was designed to charge the Ni-H battery from the PEFC in the sky automatically. It controlls the power system by using a micro computer in a mannar where the electromagnetic valve supplying hydrogen is open to recover the output voltage of the PEFC when the voltage of Ni-H battery decreased to a certain level, resulting in energy charging to the Ni-H battery and keeping the rotation of the moter. The opened electromagnetic valve is closed when the Ni-H battery full charged. Furthermore, after a certain hours operation when the output voltahge of the PEFC drops due to accumulation of impurities in hydrogen gas, the outlet valve will be opened to exhaust hydrogen containing accumulated impurities. It has been verified that as soon as the Ni-H battery voltage doropped to less than 3.8 [, the hydrogen inlet valve opened then the output of the power source increased suddnly to around 7 [.

Abstract: The high resolution and better recovery performance with distributed MIMO radar would be significantly degraded when the target moves at an unknown velocity. In this paper, we propose an adaptive sparse recovery algorithm for moving target imaging to estimate the velocity and image jointly with high computation efficiency. With an iteration mechanism, the proposed method updates the image and estimates the velocity alternately by sequentially minimizing the norm and the recovery error. Numerical simulations are carried out to demonstrate that the proposed algorithm can retrieve high-resolution image and accurate velocity simultaneously even in low SNR.

Abstract: In this paper, the widespread no-wait flowshop in industries is considered with sequence dependent setup times to minimize makespan. A hybrid iterated greedy framework is constructed. A destruction-reconstruction procedure and a composite local search are introduced to improve the initial solution, respectively. To enhance the diversification of the proposal, a solution acceptance criterion is adopted to accept a worse solution with a probability. An efficient hybrid iterated greedy algorithm is investigated for the considered problem. The proposal is compared with the existing best deterministic heuristics and non-deterministic algorithm on Taillards benchmark instances. Experimental results show that the proposal gets best performance against the deterministic heuristics. The proposed algorithm outperforms the non-deterministic one on most instances with the same computation-time.

Abstract: The paper presents a novel unity-gain phase shifter. Based on the voltage control all-pass filter using an analogue multiplier along with a frequency-to-voltage converter, this approach can theoretically both provide unity-gain and maintain a predetermined phase shift constant over a wide frequency range. As no complicated calculation circuit is required, the proposed scheme can be implemented using a simple hardware circuit. Some experimental results are provided to verify the validity of the proposed scheme.

Abstract: A single-phase two-switch SEPIC AC to DC converter is proposed in this paper. The boosting supply of the input is controlled by PWM of the power stage, while the desired DC output is PWM controlled. Since both the input boost supply and the output supply can be controlled independently, a fast transient response can be maintained at both the input for active current wave shaping and at the output for good output regulation. In addition, independent control of the multiple outputs provides the strong decoupling necessary and hence good transient response. Finally, some experimental results are presented for verification.