Many materials in nature exhibit excellent mechanical properties. In this study, we evaluated the bionic bumper structure models by using nonlinear finite element (FE) simulations for their crashworthiness under full-size impact loading. The structure contained the structural characteristics of cattail and bamboo. The results indicated that the bionic design enhances the specific energy absorption (SEA) of the bumper. The numerical results showed that the bionic cross-beam and bionic box of the bionic bumper have a significant effect on the crashworthiness of the structure. The crush deformation of bionic cross-beam and box bumper model was reduced by 33.33%, and the total weight was reduced by 44.44%. As the energy absorption capacity under lateral impact, the bionic design can be used in the future bumper body.

The energy needed for highly efficient heat transfer has shown a continuous growth, as the energy reduction. For highly efficient power convection, gas turbine is an important device at present. But, the design of highly efficient gas turbine is limited by the temperature and the material’s temperature resistance around the inlet. One part of the inlet need to be protected from burning out is transition piece. A bionic thermal surface with rib turbulators is designed according to the turbulence function of alopias’ branchial arches and is evaluated for thermo-protection enhancement in a simplified gas turbine transition piece using computational fluid dynamics (CFD) simulation. With the given diameter (Φ = 10.26 mm) of the impinging hole, three different horizontal distances (S) from impinging holes to the front of first-row rib were solved, which were S₁ = 20 mm, S₂ = 40 mm, and S₃ = 60 mm, respectively, in case 1. But, the results revealed that S is not a significant influence factor on heat transfer efficiency. The cooling coefficient increases from 0.194 to 0.198 when the distance varies from S₁ to S₃. In case 2, rib turbulator width (W) and height (H) have been studied in ranges from 0.5 × Φ to 1.5 × Φ. All of the numerical results indicated that the best size of the rib turbulators could improve the heat transfer efficiency to 32.5%, when comparing with the smooth surface. All of the comparisons will benefit the structural design of heat transfer, which could be used for solving more severe problems in thermo-protection.

Gas turbine is a widely-used propulsion device for power convection in marine dynamical system. Conventional coolants such as impingement cooling and thermal protection material have lower convective heat transfer efficiency on the...

The gas turbine transition piece was simplified to a one-four cylinder double chamber model with a single row of impinging holes in the outer wall. Heat transfer augmentation in the coolant chamber was achieved through the use of pin fin structure and mist cooling, which could increase the turbulence and heat transfer efficiency. The present research is focused on heat transfer and pressure characteristics of the impinging cooling in the coolant chamber using FLUENT software. With the given diameter of impinging hole, pin fin diameter ratios have been numerically studied in ranges from 1 to 2. Three different detached were simulated. The impinging cooling performance in all cases was compared between single-phase and two-phase (imported appropriate mist) flow in the coolant chamber. All the simulation results reveal that the factors of and have significant effects on the convective heat transfer. After the pin fin structure was taken, the resulting temperature decrease of 38.77 K at most compared with the result of structure without pin fins. And with the mist injecting into the cooling chamber, the area weighted average temperature got a lower value without excess pressure loss, which could satisfy the more stringent requirements in engineering.

The use of optimization in a simulation-based design of automotive, aerospace and consumer products has become a common trend today. Designers are faced with the continuous challenge of reducing manufacturing costs and design cycle times while improving the systems performance and reliability. In practical design, sequential linear programming (SLP) is very popular because of its inherent simplicity and easy availability. However, the inherent conceptual simplicity makes the SLP techniques not globally convergent. This research presents a new algorithm that uses a linearization error and an interior point trust-region method in SLP to truss structures that is both considered sizing and configuration problems. The algorithm may be suitable for large optimization problems where time is a constraint and the optimization may be stopped before convergence is achieved. Results of application studies are presented, illustrating the applicability of the proposed algorithm.