Applied Mechanics and Materials Vols. 427-429

Abstract: SCR (Selective Catalytic Reduction) is widely used as a good solution of reducing NOx emissions. For NOx emissions and exhaust noise for heavy-duty diesel vehicles, the paper studied the acoustic performance for the integrated system of SCR and muffler. By analyzing the action of the perforated pipe, the exhaust pressure loss and the impact on the performance of the integrated system, the integrated system was developed for heavy-duty diesel vehicles to solve the technical problem on the integration and performance optimization for the SCR system and muffler structure. Extrusion-type vanadium-based catalyst replaces the current coated-type catalysts, and improves the reduction efficiency. The two-stage rough and fine filter and the heating device for the urea pump are designed to increase the adaptability of the SCR system. The research shows that through the structural improvements, the exhaust noise is reduced by 28.5dB.

Abstract: IA method is proposed here to recognize wheels pose and position parameters with computer vision aiming to the need of measuring wheel moving track in suspension bench testing. Firstly, several markers are fit on the target wheel manually. Secondly, image coordinates of character points is calculated with image processing method and least square ellipse fitting algorithm. At last, wheels pose and position parameters are calculated with rigid body motion POSIT algorithm, and then wheel moving track is measured in test. The algorithm of wheels pose and position parameters in bench testing based on the computer vision here will supply the base under the realization of the moving wheels pose and position parameters recognizing in real time.

Abstract: Based on the characteristics of rolling bearing vibration signals in oil drilling rig and the operation principles of oil drilling equipments, a signal transmission strategy combining wireless communication technology and signal line transmission is proposed. A reusing equipment of current loop bus time-sharing switching is innovatively designed. By adopting wireless time-sharing control and switching technology, the transmission of multi-road high-frequency vibration signals is completed by means of a high quality shielded coaxial cable. The fixture greatly simplifies the wiring connection mode and reduces the patch number. Thus, the equipment cost is lowered and higher reliability of system is achieved. The fixture realizes the real-time and efficient transmission of vibration signal of rolling bearing in oil drilling rig.

Abstract: The U-shaped pipe located in the compressor piping system of the lyophilizer is studied in this paper. Its finite element modal analysis is carried out through the software ABAQUS, and at the same time, the experimental modal analysis is conducted by the software LMS Test.lab and its corollary equipment. Through the comparison between the finite element modal analysis results and the experimental modal results, it can be seen that the two results have good consistence, which verifies that the finite element model is reasonable. This paper provides reference for the further studies of the curving pipe vibration.

Abstract: Aiming at the problems presented in the design of large-size vessels, structure optimization of the pressure vessel with large opening and reinforcement is mainly discussed. Firstly, 3D finite element model was established for the pressure vessel with large opening. Then, the local equivalent stress of the vessel with large opening in the thermal stress coupled field is analyzed based on ANSYS software. Secondly, taking the wall thickness of tank body and connecting pipe, the width and thickness of reinforcement pad as design variables, allowable stress as constrain condition, different structure schemes were proposed. Finally, the optimal scheme was determined through analyzing and comparing different schemes.

Abstract: Dual-stator toroidal motor is a new type of motor. The basic structure and principle of the motor were introduced. The state equations of toroidal motor were presented, the response considering speed fluctuations of the motor was given as well. The objection function was given, and the optimal servo of the motor was designed. The control strategy was used to remove the speed fluctuations and realize desired speed tracking. The state feedback control scheme was obtained and the control signals were also presented. Small speed track errors were achieved and the speed fluctuations of the motor system were eliminated. The results justify the validity of the servo, and offer meaningful instruction for further research and practical application of the novel motor.

Abstract: The impeller is key element that brings about negative pressure adsorption. The efficiency of the impeller will determine the adsorption capacity of robot. In this paper, physical model is built based on the theory of fluid dynamics by taking a common high speed rotation of impeller as a research object. The basic parameters and boundary conditions are set and a 3D fluid dynamic simulation is done based on FloEFD. The factors such as blade curve, rotational speed and air inlet velocity which have effect on surface flow field impeller are investigated. Then the results are shown by figures and the study analysis is carried on.

Abstract: On the basis of dual-spin projectile multi-body characteristics, the angular motion model is established in the quasi-body coordinates. Through linearization, the system dynamic stability factor and gyroscopic stability factor are obtained by differential equations characteristic roots. There is also informative to compare the dual-spin projectile gyroscopic stability factor to the conventional rigid projectile results. The comparison can be viewed where the influence of the spin rates ration γ_f/γ_a and the ratio of inertia moments C_f/C_a on the ratio S_g/S^y_g of the gyroscopic stability factors. Through the numerical example, the dual-spin projectile has a similar stability to that of a conventional rigid projectile, and the curves of the relationship between the ratio S_g/S^y_g of the gyroscopic stability factors with the ratio of spin rates γ_f/γ_a and the ratio of inertia moments C_f/C_a are got by simulation.

Abstract: This paper analyzed the spatial catapult dynamics of spatial catapult on-orbit separation problem equipped with a separate rail, providing the basis for separation of ground testing and separation system design. under the premise of separation requirements as well as the arbitrariness of locations of the spring and rail, By using newtonian dynamics, as well as momentum theorem and angular momentum theorem, the dynamic model of the separating motion was formulated in translational inertial reference frame .Solution examples with different initial conditions were offered ,and the accuracy of the model is verified via the solution of numerical simulation.

Abstract: Modeling and simulation method of unsteady aerodynamics on morphing wings were investigated. The Unsteady Vortex Lattice Method is employed to model the unsteady aerodynamics of 3-D potential flow field surrounding the wing. An UVLM computer code was then developed and validated for numerical simulation. A morphing wing which changes its dihedral angle with constant angular velocity was investigated by the code, and the lift, induced drag, and pitching moment coefficients time histories were obtained. The results show that the UVLM code is an effective tool for simulations of unsteady aerodynamics on morphing wings.