Advanced Materials Research Vol. 625

Abstract: The impact on water of aeronautical structures is likely to turn into a tragic event. In view of this, it is essential to develop new solutions to design worthy structure that can assure best behavior. The Smoothed Particles Hydrodynamics (SPH) is a mesh-free interpolation method which is a recent numerical analysis technique. One example of water impact based on SPH is presented here, which aims at an accurate numerical simulation of Fluid-Structure Interaction(FSI) in free surface flow context. The example describes a rigid sphere impacting onto water, presenting the global impact behavior as well as comparing the impact coefficient with analytical and experimental results. The SPH method is proved to be a reliable and efficient numerical tool.

Abstract: Based on secondary reversal reentry dynamics and the drag acceleration - energy (D-E) profile, a new reentry trajectory planning and guidance method is present. Since the D-E profile is obtained from interpolating the upper and lower boundary of the reentry corridor, it has the ability to guide the vehicle to the maximum down-range and cross-range. The secondary bank reversal mode is implemented to ensure terminal guidance accuracy and reduces the difficulty of tracking control. The planning taking the vertical and horizontal movement of the vehicle into account by adjusting the reversal point and the bank angle to satisfy range and terminal heading angle requirement.

Abstract: The strong swirl turbulent flow in hydrocyclone causes major difficulties in modeling their internal solid-liquid flows. In this thesis, the strongly swirling turbulent flow in solid-liquid hydrocyclone separators is simulated by using Reynolds stress equation models (RSM) of FLUENT applications to use the body-fitted and partition meshes. The results give some new understanding on 3D velocity distribution. According to the numerical simulation results, the lab experiment is implemented in this thesis.the lab simulation system and real-time data process system are set up to gather the parameters in the simulation system. the relation curve of production capacity-inlet pressure and separation property-inlet pressure are analyzed. Comparing with the numerical simulation ,the result is reasonable.

Abstract: The liquid phase experiment is finished ,and the relation curve of input- pressure and input-flow、output-flow、distributary rate are worked out.We are bout to calculate the production capacity and define the best distribution rate of the operation parameters.At the same time , the solid-liquid phase separating experiment are made too and we conclude the relation curve of input-pressure and consistency 、separating efficiency .Comparing with the numerical simulation ,the result is reasonable.

Abstract: Heavy truck needs to use the vibration reduction technology to improve its quality. Nowadays, it is a useful and effective way for vibration reduction that by employing the proper Powertrain Mounting Systems (PMS) to reduce the vibration. One useful method to develop more effective mounting systems is through optimization techniques. Sequential Quadratic Programming (SQP) is an effective optimization technique. In this paper, design optimization of powertrain mounting system based on SQP method for vibration control is presented. The optimization objective is to find the highest decoupling ratio of the each mount while selecting the stiffness and orientations of individual mount. The constraints are imposed to keep the desired decoupled ratio in each orientation and the frequency corresponding to the decoupled ratio. A case study is given to validate the proposed method. The result shows that the value of optimized system, such as decoupling ratio, is improved significantly. Therefore, the method proposed in this paper is effective for the optimization of powertrain mounting system.

Abstract: Roller element bearing is an important part of mine ventilating fan. The management and maintenance of the equipment is very important. Therefore, it is necessary to employ fault diagnosis process to the roller element bearing. In this paper, mechanics properties of roller element bearing are analyzed. Then, Radial Basis Function (RBF) neural network is used for the fault diagnosis of the roller element bearing. The structure and inference of RBF network are discussed in detail. The roller element bearing fault diagnosis model is established based on RBF network. A case study is given. The proposed method is applied to the fault diagnosis of roller element bearing. The result shows that the proposed method can improve efficiency of the fault diagnosis.

Abstract: The design of the steering system is a very important part of the vehicle design, the steering system have a direct impact to the vehicle's handling and stability, the steering portability as well as the driver's work intensity and efficiency. The paper introduced the composition and characteristics of the vehicle's steering system. Analysis of the basic requirements and key technologies of the vehicle's steering. According to the applications and the advantages and disadvantages of the existing two-wheel steering system, advance a concept of four-wheel steering system, analysis of the structure of the four-wheel steering technology and the problems to be solved. In addition,studied the application situation of the power steering system in the vehicle steering mechanism from mechanical mechanics.

Abstract: This paper is based on the complex multiple vehicular missile launch simulation model, researches the influence of combustion jet flow to the initial disturbance of missile. It establishes rigid-flexible coupling dynamic model by use of Adams and Ansys, and calculates the value of combustion jet flow field in missile box by means of Fluent. The rigid-flexible coupling dynamic simulation for the whole launch process is carried out. The study results show that the simulation with loading jet flow can accurately tend to real launch environment, it has great significance to optimize the simulation and to improve the accuracy of the simulation.

Abstract: As for the issue of ship-board rocket gun launch, the research on the influence of sea condition on initial disturbances of rockets was conducted. The launch system was simplified and the dynamics model was established. The energy spectral density of motion of ship in irregular waves was calculated based on ocean wave energy spectrum and the dynamic response of launch system was studied under three kinds of sea conditions. The result indicates that amplitudes of pitch and yaw increase, however, the rolling decreases when the sea condition level rises.

Abstract: Because of the flexible kinematic characteristic of five-axis-linkage machining center it is widely used to process complex parts. The milling head is the key functional component of the five-axis machining center, therefore study of the milling head is of vital importance. The A/C axes bi-rotary milling head is the most common used structures. The current mechanical A/C axes bi-rotary milling head is mostly with large volume and small rotation range. This paper presents an A/C axes bi-rotary milling head with zero transmission in small volume. To understand the kinetic characteristics of the A/C axes bi-rotary milling head with zero transmission, we apply D-H parameter method to establish displacement equations, speed equations, and acceleration equations. SolidWorks is then utilized to build the virtual prototyping model of the designed mechanism. Motion module of SolidWorks is also used to carry out the kinematics simulation. The experimental results show that the mechanism could achieve the rotation of A/C axes and smooth motion trajectory. The rotation range of A-axis could reach ±120°.