摘要：To design effective and easy-to-manufacture conductive heat channels, a heuristic method by emulating the natural branch systems is suggested. The design process of the method is divided into two steps, which are the principal channel design and the lateral channel design. During the process, the width of each channel is controlled by the bifurcation law, and the end point of the channel is located at the point with the maximum temperature while the start points of the principal channel and the lateral channel are respectively determined by the location of the heat sink and the law of the minimum thermal resistance. Four design examples with different boundary conditions are studied by the suggested method, and the design results are compared with that of the traditional structural topology optimization method. Not only lower maximum temperature and relatively uniform distribution of temperature are obtained by the suggested method, but also straight channels are achieved without gray element, which is easy to manufacture. The suggested method inspired by the natural branch systems can provide an effective solution for heat channel design in the heat dissipation structures.

摘要：In order to establish the design methodology of an ultra micro centrifugal compressor, which is the most important component of an ultra micro gas turbine unit, a 10 times size of the final target compressor （impeller outer diameter 40 mm, corrected rotational speed 220,000 r/min） was designed. The problems to be solved for downsizing were examined and a 2-dimensional impeller was chosen as the first model due to its productivity. The conventional 1D prediction method and CFD were used. The prototyped compressor was tested by using cold air at the reduced speed of 110,000 r/min. Following to the 10 times model, a 5 times size of the final target model having fully 3-dimensional shape （impeller outer diameter 20mm, corrected rotational speed 500,000 r/min） was designed and tested by using hot gas at the reduced speed of 250,000 r/min.

摘要：High-speed machine tool working table restrains the machining accuracy and machining efficiency,so lightweight design of the table is an important *** nature,leaf has developed a plate structure that maximizes the surface-to-volume *** can be seen as a plate structure stiffened by *** with a high-speed machine tool working table,leaf veins play a role of supporting part which is similar to that of stiffening ribs,and they can provide some new design ideas for lightweight design of the *** this paper,distribution rules of leaf veins were investigated,and a structural bionic design for the table was achieved based on regulation of leaf ***,statistical analysis on geometric structure of leaf veins was carried out,and four distribution rules were ***,relevant mechanical models were developed and analyzed in finite element *** on the results from mechanical analysis on those relevant models,the four distribution rules were translated into the design rules and a structural bionic design for the working table was *** simulation and experimental verifications were carried out,and results showed that the average displacement of the working table was reduced by about 33.9%.

摘要：In the one-gravity environment on the ground, the simulation of the contact process of two flying objects in the zero-gravity environment of space has been a challenging issue since humans first explored space by flying objects. Hardware-in-the-loop （HIL） simulation is an important and effective method to test the usability, reliability, and safety of real docking mechanisms in space. There are four main issues for HIL simulation systems： Design of simulators capable of high frequency response, high motion precision, high velocity, and rapid acceleration; compensation for simulation distortion; design of a control model for the HIL simulation process; and experimental verification. Here, we propose a novel HIL simulator system with a 6-DOF 3-3 perpendicular parallel mechanism and a 3-DOF 3-PRS parallel mechanism; discover the principle of simulation distortion; present distortion compensation models for the force measurement system, dynamic response, and structural dynamics of the simulator; and provide a control model for the HIL simulation process. Two kinds of experiments were performed on the pas- sive-undamped elastic rod and the docking mechanisms to test their performances and to verify the effectiveness and usability of the HIL simulator. The HIL simulation system proposed in this paper is useful for developing space docking, berthing, refu- eling, repairing, upgrading, transporting, and rescuing technologies.

摘要：Dragonflies have naturally high flying ability and flight maneuverability,making them more adaptable to harsh ecological *** this paper,a flapping wing bionic air vehicle with three-degrees-of-freedom is designed and manufactured by simulating the flight mode of ***,the body structure of dragonfly was analyzed,and then the design scheme of flapping wing micro air vehicle was proposed based on the flight motion characteristics and musculoskeletal system of *** optimizing the configuration and using Adams to do kinematic simulation,it is shown that the designed structure can make the wings move in an“8”shape trajectory,and the motion in three directions can maintain good consistency,with good dynamic *** on CFD simulation method,we analyzed that the wing has the conditions to achieve flight with good aerodynamic performance at the incoming flow speed of 5 m s^(-1)and frequency of 4 Hz,and studied the effects of angle of attack and flutter frequency on the aerodynamic performance of the ***,the force measurement test of the aircraft prototype is carried out using a force balance and a small wind *** test results show that the prototype can provide the average lift of 3.62 N and the average thrust of 2.54 N,which are in good agreement with the simulation results.

摘要：The band structure of the confined states is calculated for Si/SiGe multi-quantum well infrared photodetector(M-QWIP).The influence of the Ge component in pseudosubstrate on the energy band structure of Si/Si0.54Ge0.46 multi-quantum wells(MQWs) is *** is found that the high energy levels in the MQWs move up while the low energy levels move down as the Ge component in pseudosubstrate *** influence of the barrier width on the energy band structure of MQWs is also studied based on the 6 × 6 k.p *** results show that the Si barrier between 5 nm and 10 nm is optimized to enhance the intersubband absorption in the MQWs.

摘要：In order to support the functional design and simulation and the final fabrication processes for functional surfaces,it is necessary to obtain a multi-scale modelling approach representing both macro geometry and micro details of the surface in one unified *** on the fractal geometry theory,a synthesized model is proposed by mathematically combining Weierstrass-Mandelbrot fractal function in micro space and freeform CAGD model in macro *** issues of the synthesis,such as algorithms for fractal interpolation of freeform profiles,and visualization optimization for fractal details,are addressed.A prototype of the integration solution is developed based on the platform of AutoCAD's Object ARX,and a few multi-scale modelling examples are used as case *** the consistent mathematic model,multi-scale surface geometries can be represented ***,the visualization result of the functional surfaces shows that the visualization optimization strategies developed are efficient.

摘要：A kind of active vibration control method was presented through optimal design of driving load of multi-body system with quick startup and brake. Dynamical equation of multi-body system with quick startup and brake was built, and mathematical model of representing vibration control was also set up according to the moving process from startup to brake. Then optimization vibration control model of system driving load was founded by applying theory of optimization control, which takes rigid body moving variable of braking moment as the known condition, and vibration control equation of multi-body system with quick startup and brake was converted into boundary value problem of differential equation. The transient control algorithm of vibration was put forward, which is the analysis basis for the further research. Theoretical analysis and calculation of numerical examples show that the optimal design method for the multi-body system driving load can decrease the vibration of system with duplication.

摘要：Increasing demand for downsizing of engines to improve CO2 emissions has resulted in renewed efforts to improve the efficiency and expend the stable operating range of the centrifugal compressors used in petro-chemical equipment and turbochargers. The losses in these compressors are dominated by tip clearance flow. In this paper, the tip clearance flow in the subsonic impeller is numerically investigated. The nature of the tip clearance in inducer, axial to radial bend and exducer are studied in detail at design and off-design conditions by examining the detailed flow field through the clearance and the interaction of the clearance flow with the shear effect with the endwalls. The correlation between blade loading and span wise geometry and clearance flow at different locations are presented.

摘要：Soft machines are combinations of hard and soft active materials, thus the coupling and interaction between soft and hard components dictate the performance of soft machines. Structural optimization has been intensively used for design of conventional hard machines, while, to our best knowledge, few attempts have been made towards optimal design of soft machines. Here, we describe the sizing optimization problem of a dielectric elastomer(DE) actuated mechanical amplifier, and achieve the optimal design through combination of a commercial finite element method(FEM) software and an optimization automation *** then design, fabricate and demonstrate a locomotive soft machine driven by DE actuator with amplified displacement *** methodology and results present here open the door towards optimal designs of active materials based soft machines.