Time filter

Source Type

Fu K.,Harbin Marine Boiler And Turbine Research Institute | Fu K.,University of Sydney | Chang L.,University of Sydney | Zheng B.,Tongji University | And 2 more authors.
Materials and Design | Year: 2015

In this study, attempts have been made to estimate the representative stress-strain relation of metallic materials from indentation tests using an iterative method. Finite element analysis was performed to validate the method. The results showed that representative stress-strain relations of metallic materials using the present method were in a good agreement with those from tensile tests. Further, this method was extended to predict representative stress-strain relation of ultra-thin molybdenum films with a thickness of 485. nm using nanoindentation. Yielding strength and strain hardening exponent of the films were therefore obtained, which showed a good agreement with the published data. © 2014 Elsevier Ltd.

Qiu A.,South China University of Technology | Fu K.,Harbin Marine Boiler And Turbine Research Institute | Fu K.,University of New South Wales | Lin W.,South China University of Technology | And 2 more authors.
Materials and Design | Year: 2014

The impact responses of typical laminates are investigated umerically in this research. Delamination responses among plies and fibre and/or matrix damage responses within plies are simulated to understand the behaviours of laminates under different impaction conditions. Damage resistance of a laminate is highly dependent upon several factors including geometry, thickness, stiffness, mass, and impact energies (impact velocities), which are here considered by the finite element (FE) method. Three groups of composite laminates are simulated and the numerical results in general are in good agreement with corresponding experiments. Models containing different stacking sequences and impact energies are built to study their influence on impact responses and demonstrate that clustered (or nearly clustered) plies in the laminate can effectively reduce the degree of interface damage. Models containing different indenters and plate shapes are also built to systematically study their influence on the low-speed drop-weight behaviour of composite laminates. Suggestions are proposed for designing impact tests for particular purposes. © 2014 Elsevier Ltd.

Fu W.,Shihezi University | Li S.,Shihezi University | Sun J.,Harbin Marine Boiler And Turbine Research Institute | Yang H.,Shihezi University | Kan Z.,Shihezi University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

Cultivation technology of mulching film coverage, drip irrigation under film and hole sowing above film is adopted for corn cultivation in Xinjiang. Aiming at technical requirement of precision metering hole sowing for corn above film and according to the principle of compulsory clamping, a new method of mechanical compulsory clamp-type of precision metering corn seed sowing was put forward in this paper. Through measuring physical mechanics characteristics of three types of corn seeds as well as deeply and theoretically analyzing the process of seed picking and seed charging, mathematical model was set up, so as to provide the basis for the structural design of seed sowing device. Bench test for preproduction seed sowing device was carried out on seed sowing device test bed of JPS-12 computer visual technology, so as to validate that compulsory clamp-type of seed sowing device had good adaptability to corn of small round and small flat shapes, as well as to verify that single grain rate was greater than 85%, which meeting the requirement of precision seed sowing.

Zhao N.,Harbin Engineering University | Wen X.,Harbin Marine Boiler And Turbine Research Institute | Li S.,Harbin Engineering University
Proceedings of the ASME Turbo Expo | Year: 2015

Coolant is one of the important factors affecting the overall performance of the intercooler for the intercooled cycle marine gas turbine. Conventional coolants such as water and ethylene glycol have lower thermal conductivity which can hinder the development of highly effective compact intercooler. Nanofluids that consist of nanoparticles and base fluids have superior properties like extensively higher thermal conductivity and heat transfer performance compared to those of base fluids. This paper focuses on the application of two different waterbased nanofluids containing aluminum oxide (Al2O3) and copper (Cu) nanoparticles in intercooled cycle marine gas turbine intercooler. The effectiveness-number of transfer unit method is used to evaluate the flow and heat transfer performance of intercooler and the thermophysical properties of nanofluids are obtained from literature. Then the effects of some important parameters such as nanoparticle volume concentration, coolant Reynolds number, coolant inlet temperature and gas side operating parameters on the flow and heat transfer performance of intercooler are discussed in detail. The results demonstrate that nanofluids have excellent heat transfer performance and need lower pumping power in comparison with base fluids under different gas turbine operating conditions. Under the same heat transfer, Cu-water nanofluids can reduce more pumping power than Al2O3-water nanofluids. It is also concluded that the overall performance of intercooler can be enhanced when increasing the nanoparticle volume concentration and coolant Reynolds number and decreasing the coolant inlet temperature. Copyright © 2015 by ASME.

Gao J.,Harbin Engineering University | Zheng Q.,Harbin Engineering University | Xu T.,Harbin Marine Boiler And Turbine Research Institute | Dong P.,Harbin Engineering University
Energy | Year: 2015

The TLV (tip leakage vortex) breakdown occurs under some conditions in modern turbines, which leads to extra vortex breakdown losses, but the mechanisms of vortex breakdown and its influencing factors remain unclear. This paper computationally investigates the effects of inlet conditions on the TLV dynamics in an unshrouded turbine. The TLV dynamics analysis is first shown, and then the effects of inlet CBL (casing boundary layer) parameters and flow incidence on the TLV breakdown and loss are investigated respectively. Based on these, a comparison of effects of different inlet conditions on tip leakage mixing loss is examined. Results indicate that the increased CBL thickness and turbulence intensity increases the adverse-pressure gradient in the rear part of the blade tip in varying degrees, but has a minor effect on TLV breakdown location. An increased incidence leads both to the reduction of the initial streamwise velocity on the vortex core and the adverse-pressure gradient in the rear part of the blade tip. Overall, as the incidence increases, the TLV breakdown location moves first upstream and then downstream. All these mean that the TLV initial state is another influencing factor on its breakdown. © 2015 Elsevier Ltd.

Discover hidden collaborations