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Dan S.,Harbin Institute of Technology | Jianzhi W.,Harbin Marine Boiler And Turbine Research Institute | Huilin L.,Harbin Institute of Technology | Yunhua Z.,Harbin Institute of Technology | And 3 more authors.
Powder Technology | Year: 2010

Flow behavior of gas and particles is performed by means of gas-solid two-fluid model with the second-order moment model of particles in the bubbling fluidized bed. The distributions of velocity and moments of particles are predicted in the bubbling fluidized beds. Predictions are compared with experimental data measured by Jung et al. (2005) in a bubbling fluidized bed and Patil et al. (2005) experiments in a bubbling fluidized bed with a jet. The simulated second-order moment in the vertical direction is on average 1.5-2.3 times larger than that in the lateral direction in the bubbling fluidized bed (Jung et al., 2005). For a bubbling fluidized bed with a jet, the ratio of normal second-order moment in the vertical direction to in the lateral direction is in the range of 0.5-2.5 (Patil et al., 2005). The bubblelike Reynolds normal stresses per unit bulk density used by Gidaspow et al. (2002) are computed from the simulated hydrodynamic velocities. The simulated bubblelike Reynolds normal stresses in the vertical direction is on average 4.5-6.0 times larger than that in the lateral direction in the bubbling fluidized bed (Jung et al., 2005). The predictions are in agreement with experimental second-order moments measured by Jung et al. (2005) and porosity measured by Patil et al. (2005). © 2010 Elsevier B.V. All rights reserved.


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 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.


Fu H.,Harbin Engineering University | Wang Y.,Harbin Engineering University | Jin D.,Harbin Marine Boiler And Turbine Research Institute
Chinese Control Conference, CCC | Year: 2016

Aiming at complex characteristics of magnetic flux leakage signal, and it is hard to describe geometric features of pipeline defect. A novel approach based on improved particle swarm optimization and Least Squares Support Vector Machines (LSSVM) algorithm was proposed to reconstruct pipeline defect in this paper. The nuclear function parameter and penalty parameter are vital factors which determine performance of Least Squares Support Vector Machines. Use improved particle swarm optimization optimize the parameters of LSSVM automatically, insuring the accuracy of parameter choice. This method was used to pipeline defect reconstruction, simulation results demonstrate that method can break through the difficulty of magnetic flux leakage signals described defect geometrical characteristics, improving the reconstruction accuracy, with a highly practice value. © 2016 TCCT.


Wang Y.,Harbin Engineering University | Fu H.,Harbin Engineering University | Lin D.,Harbin Marine Boiler And Turbine Research Institute
Chinese Control Conference, CCC | Year: 2016

A novel image segmentation for infrared small target of agriculture and forestry fire is proposed in this paper. Usually, Maximum Variance Image Segmentation method (Otsu) is a popular non-parametric method in image segmentation. However, it needs a lot computation and has poor real-time quality. Thus it is hard to be wide applied in many situations. To over come this issue, a constructive approach to obtain optimal threshold of between-class variance as fitness function for Otsu by particle swarm optimization (PSO), reduce the amount of computation and improve real-time performance. The performance of the proposed method is evaluated through infrared small target of agriculture and forestry fire. The experimental results demonstrate the effectiveness of the proposed method. © 2016 TCCT.


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.


Gao J.,Harbin Engineering University | Zheng Q.,Harbin Engineering University | Niu X.,Harbin Marine Boiler And Turbine Research Institute | Yue G.,Harbin Engineering University
Applied Thermal Engineering | Year: 2016

A significant portion of flows over a modern high-pressure turbine blade tip is transonic, and the transonic tip leakage flows lead to significant aerodynamic losses and high heat loads onto the blade tips. This paper aims to develop a deeper understanding of the transonic tip leakage flow physics and its influence on the loss mechanism and blade-tip heat transfer. Three-dimensional (3D) Reynolds-averaged Navier-Stokes (RANS) calculations were performed using the ANSYS CFX 14.5 numerical prediction code, adopting the SST k-ω turbulence model to investigate the sensitivity of aerothermal performance of transonic tip flows to tip clearances in a RT27a turbine cascade. The transonic tip leakage flow pattern within the tip gap, the flowfield downstream of the cascade, and the blade tip heat transfer distribution are studied. The numerical results give a reasonable agreement with the experimental data. The tip aerodynamics and surface heat transfer variations with tip clearances are opposite between leading and trailing edge regions of blade tips, and tip clearance effects on the former are relatively small. As the tip clearance increases, the shock wave reflections are delayed but more evident, and it therefore leads to reduced leakage massflow density and decreased heat loads on the rear part of blade tips. Despite this, since the leakage flow near the leading edge of blade tips remains subsonic resulting in increased leakage mass flowrate and tip heat transfer, the leakage losses and overtip heat loads are increased with the increasing tip clearance. © 2016 Elsevier Ltd


Zhao Y.,Harbin Engineering University | Jia R.,Harbin Engineering University | Jia R.,Harbin Marine Boiler And Turbine Research Institute | Jin N.,Harbin Engineering University | He Y.,Harbin Engineering University
Information Sciences | Year: 2016

In order to take full advantage of resources for navigation and reduce risks, this paper proposes a novel method of fleet deployment based on route risk evaluation. Dempster-Shafer(D-S) evidence theory is applied in order to construct the route risk evaluation model, considering the main environmental factors affecting navigational safety. A novel optimization model of fleet deployment is thus established and the firefly algorithm used to solve the problem. The experimental results show the effectiveness and practicality of the new model and algorithm. © 2016 Elsevier Inc.


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: 2016

With the rapid improvement of equipment manufacturing technology and the ever increasing cost of fuel, engine health management has become one of the most important parts of aeroengine, industrial and marine gas turbine. As an effective technology for improving the engine availability and reducing the maintenance costs, anomaly detection has attracted great attention. In the past decades, different methods including gas path analysis, on-line monitoring or off-line analysis of vibration signal, oil and electrostatic monitoring have been developed. However, considering the complexity of structure and the variability of working environments for engine, many important problems such as the accurate modeling of gas turbine with different environment, the selection of sensors, the optimization of various data-driven approach and the fusion strategy of multi-source information still need to be solved urgently. Besides, although a large number of investigations in this area are reported every year in various journals and conference proceedings, most of them are about aeroengine or industrial gas turbine and limited literature is published about marine gas turbine. Based on this background, this paper attempts to summarize the recent developments in health management of gas turbines. For the increasing requirement of predict-And-prevent maintenance, the typical anomaly detection technologies are analyzed in detail. In addition, according to the application characteristics of marine gas turbine, this paper introduces a brief prospect on the possible challenges of anomaly detection, which may provide beneficial references for the implementing and development of marine gas turbine health management. © Copyright 2016 by ASME.

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