Advanced Materials Research Vol. 1051

Abstract: In various traditional technologies of solving the heat-dissipation problem for LED, all of these methods exhaust the waste heat into the environment and cause the more serious greenhouse effect. In this article, we present a new heat-dissipation method for high brightness 10W LED bulb using a novel structure of thermoelectric chip module. Evidence illustrates that graphite performs both the best heat-absorption material as well as the superior heat-dissipation material for LED thermoelectric chip module. Besides, the double-layered structure with graphite as heat-conduction material of LED thermoelectric module could create the most temperature-difference and thus conduct the highest output power. It implies that double-layered structure of LED thermoelectric chip module with graphite as heat-conduction material is the optimal structure for heat-dissipation of 10W LED bulb.

Abstract: Using fluent software simulations to analysis the temperature field and the velocity field of the equal and changing diameter condensing coils at different positions of heat pump water storage tank, and made experiment of R1234-ze on the heat pump water heater storage tank with equal and changing diameter condensing coils ,experimental analysis and simulation results show that changing diameter condensing coils make the tank temperature raise stability, which is beneficial to the stability of the system operation.

Abstract: This paper describes the testing of wind turbine blades with tubercles in two different ways: outdoor testing and flow visualization. In the outdoor testing, the tubercle pitch was varied for turbine blade lengths of 30 cm, 40 cm, and 50 cm. The pitch-to-length ratio of approximately 1/10 to 1/16 produced the most power output. In flow visualization, both tubercle pitch and amplitude were varied. Vortices created behind the tubercles were shown to increase lift by minimizing flow separation.

Abstract: The Chinese refrigeration industry is faced with dual pressure of energy saving and emission reduction. R600a as an alternative refrigerant of R134a is environment friendly, and the alternation is very good. Firstly, this paper established a two-dimensional steady numerical calculation model of the refrigerating chamber with R600a, and studied the influence of the temperature distribution of the refrigerator’s posterior wall under different schemes on temperature field and velocity field of the refrigerating chamber. When the function of temperature distribution is T=-11.75*y, will achieve the best temperature field and velocity field, and the results are better than the original machine. Secondly, this paper studied the experimental improvement of R600a under the best temperature distribution scheme comparing with R134a.

Abstract: Influences of arc-shaped baffles turbulators (ASB) on thermal behaviors in a solar air heater channel are studied. In the experiment, the ASB with three pitch ratios (P/e) are placed on the absorber plate (bottom channel wall in this case) to generate stronger turbulence intensity in the channel. The distributions of temperature and local Nusselt number contours in the absorber plate fitted with ASB are observed with thermochromic liquid crystal (TLC) sheet. The results reveal that the heat transfer increases with the decrease in P/e due to longitudinal vortex flow effect. The heat transfer from employing the ASB at P/e = 4.0, 6.0 and 8.0 is higher than the smooth channel around 116%, 120% and 127%, respectively. This indicates that the ASB pitch spacing is optimal at 8 times baffle height in the present work.

Abstract: This paper simplifies the energy regeneration-based vehicle velocity system of the hydraulic hybrid bus into a process in which the extension rod of the hydraulic cylinder drives the secondary-element variable delivery pump/motor to change its displacement. This process enables braking of the vehicle and also allows recovery of energy. Based on the mathematical model established for the system, the fuzzy self-adaptive PID controller is designed and the compared with the conventional PID controller with respect to their impact on system performance.

Abstract: In order to study the impact resistance capability of dump truck bodies floor, a simulation model of dump truck bodies floor and impact hammerheads made of metal materials were designed, and a strain test system of bodies floor under impact loading was established, a measurement of the stress of bodies floor model was made to obtain the law of stress variation about key point of truck bodies floor model. The research laid the foundation for the analysis of impact resistance capability of dump truck bodies floor using finite element method as well as provided a reference for the structural optimization of truck bodies floor.

Abstract: This paper presents a method for optimized cavitation of 3-blade type ship propeller. Cavitation flow is investigated around ship propellers experimentally. Testing of two different types of new model propellers and local type propellers are performed in this study. A 3-blades, skew angle 20 degree, developed area 50 and 35, so called model A (B3-20-50), and model B (B3-20-35) respectively, and finally a local type propeller popular used among local fisherman are compared. The results are presented in characteristic curves are related pictures. Finally, the results ate discussed, Model A and B is investigated based on existing experimental results. In addition, model C is a comparison validation to non-optimum for used to shallow-fishery and tailing Thai boat. A practical method was achieved by combining a vortex lattice lifting method and lifting surface method. The optimum circulation distribution yielding the maximum lift-to-torque ratio was computed for given thrust and chord lengths along the radius of the propeller by dividing the blade into a number of panels extending from hub to tip. The radial distribution of bound circulation could be computed by a set of vortex elements that have constant strengths. The cavitation phenomenon is appear to monograph of model A and B the better model C (local type), such as, the cavitation prediction on a hydrofoil is carried out in both steady and unsteady states. The results show good agreement in comparison with available experimental data. Furthermore, the propeller cavitation breakdown is well reproduced in the proceeding. The overall values suggest that the present approach is a practicable tool for predicting probable cavitation on propellers during design processes.

Abstract: In order to analyze the structural strength of no floor beam dump truck cargo body, this paper established cargo body finite element analysis (FEA) model with the shell elements as basic element. The sand pressure on the cargo body was calculated by Rankine active earth pressure theory, and the Hyper works (a FEA software) was used to calculate the static strength and mode of the cargo body. By calculation, stress, deformation distribution and mode parameters of the cargo body were obtained, which provided reference for the cargo body improvement.

Abstract: This study mainly investigates the influence of electronic water cooling system on high power heat generation device at different cooling water inlets with vortex fins or not, hence, heat dissipation experiments are going to carried out on the conditions of three cooling cases: hollow case I, hollow case II and vortex-fin case. From this experiment, it can be seen that the heat dissipation efficiency of hollow case I is reduced by 10% as compared to that of hollow case II, and the heat dissipation efficiency of vortex-fin case is also reduced by 10% as compared to that of hollow case I, that is, water cooling system with vortex-fin has very excellent effect on heat dissipation.