Applied Mechanics and Materials Vols. 130-134

Abstract: This work performs an oil-water two-phase flow simulation in a downhole Venturi meter to investigate the flow field and pressure characteristics with different flow and oil-water ratios. The relation between the pressure drop and the feed flow rate in the flowmeter is investigated for its optimal design.

Abstract: For a class of non-linear,time-delay and time-varying control systems with unknown interference,a compound algorithm combining classical PID with model reference adaptive control (MRAC) based on the Lyapunov approach is proposed in this paper.The compound algorithm is employed to control flow in automobile radiator’s water circulation system.The simulation and practical application show that the compound algorithm could ensure high speed response,high precision,stabilization and rubustness more effectively compared with conventional control algorithm.The algorithm is practical and worthy to be used.

Abstract: Ups and downs control was one of the main contents in control of the submersible. A new ups and downs control system was used on the submersible with piston type. Its mechanism structure and experiment platform was introduced firstly in this paper. Then the theory design, underwater experiment and finite element analysis of piston cavity was made separately to verify its design reliability and stability. The results of experiment and emulation suggest that the piston type submersible design was reasonable, feasible and practical.

Abstract: Screw pump is a special type of rotary positive displacement pump in which the flow through the pumping elements is truly axial. The objective of this study is to develop a numerical solution method for flow analysis of a twin screw pump by using a Single Rotating Reference Frame method with various boundary conditions and rotational speeds of rotor on steady state condition. Flow variable contours and plots were obtained for fluid flow inside a pump subject to pressure inlet and pressure outlet conditions using the numerical control volume method in the commercial package of FLUENT. This work needs for the analysis of flow parameters inside a screw pump in order to achieve optimum design.

Abstract: Particle Image Velocimetry combined with image processing program is used to measure the salt-out two phase flow in the volute. The velocity distribution of different phases are obtained respectively under different temperatures. The experimental results indicate that :As the increasing of discharge, the liquid velocity becomes larger; In the same radial direction, the velocity decrease as the increase of radial; As the temperature decrease , the particles become larger, and the particle velocity become smaller. Through analyzing the results, some characteristics of this kind flow in volute are obtained and some guiding advices are presented to designing the volute of two-phase flow pump.

Abstract: In this paper, we apply homotopy analysis method to solve nonlinear equation and successfully obtain the bell-shaped solitary solution to the nonlinear equation. Comparison between our solution and the exact solution shows that homotopy analysis method is effective and valid for nonlinear problems.

Abstract: This paper considers the optimal control design problem for nonlinear systems with composite disturbances. First, the original system is transformed into an augmented system without disturbances. Then with respect to the quadratic performance indexes of infinite horizon, we design an optimal controller for the augmented plant without disturbances. Thus the disturbances can unfold of the signal through the Taylor series for the form of polynomial function of time, and obtain optimal controller design approach to eliminate the general disturbance. Finally, a practical example is given to illustrate the effectiveness of the theory.

Abstract: This paper is concerned with a new numerical method of two-dimensional flow. The governing system of differential equations is transformed into an equivalent system applied over a square-grid network in order to overcome the difficulties and inaccuracies associated with the determination of characteristics near the flow boundaries. The MacCormack two-step explicit scheme with second-order accuracy is used for the solution of the transformed system of equations. The present numerical model has been used to numerically compute flow in sharply curved channel

Abstract: The feature points of test curve reflect important information of the equipment under test. The feature points are important for test report. Previous method of artificial selecting points is well targeted. However, it is low efficiency and subjectivity. A method to safe people from colossal data selection is long-cherished wish to all operators. The proposed algorithm in this paper can simulate the artificial process of feature information extraction and adjust the size of selected features according to the needs of the user. At least 100 times efficiency will be increase than artificial process.

Abstract: This paper has studied infrared target background suppression technology in the case of low SNR. In order to meet the high detection rate and the low false alarm rate, this paper presents a new infrared image background prediction method based on morphological anisotropic diffusion filtering. Experiments show that the proposed algorithm, under the condition of rolling background infrared image, has a good background predication and targeting enhancement.