Kyushu University Academic Staff Educational and Research Activities Database
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CHANGHONG HU Last modified date:2018.07.02



Graduate School
Other Organization


Homepage
http://www.riam.kyushu-u.ac.jp/ship/STAFF/hu/index.html
Academic Degree
PhD in Engneering
Country of degree conferring institution (Overseas)
No
Field of Specialization
Marine renewable energy, Ship and ocean engineering, Computational fluid dynamics
ORCID(Open Researcher and Contributor ID)
0000-0002-8308-9180
Total Priod of education and research career in the foreign country
00years00months
Outline Activities
- Research activities -
List of research projects in chronological order:

1. Investigation on slow drift damping due to viscous force acting on a cylinder
2. Environmental assessment of Mega Float
3. Field modeling of hot gas movement in a marine compartment fire
4. Large Eddy Simulation of turbulent heat convection
5. Numerical and experimental study on metallic fume diffusion in a factory
6. Development of a CIP based method for strongly nonlinear wave-body interactions
7. Development of a new ship hull form for reducing CO2 emission in a Seaway
8. Study on High-Performance FSI Simulation method
9. Study on Large-Scale Floating Wind Farms in Waves
10. Environment assessment of marine CCS by large-scale numerical simulation
11. Development of new-type floating platform for offshore wind turbine
12. Tidal current turbine wake modelling and array arrangement optimization
13. Development of next-generation CFD solver for strongly nonlinear wave-body interactions

- Education activities -
From 1995 to 2002, as an assistant professor of Kyushu University, involved in education activities.
From 2002, as an associate professor, and from 2014 as a professor of Kyushu University, in charge of a coorperative laboratory in the Department of Earth System Science and Technology, Interdisciplinary Graduate School of Engineering Sciences.
Research
Research Interests
  • Development of new-type floating platform for offshore wind turbine
    keyword : Offshore wind energy, new-type floating platform
    2012.04~2016.03.
  • Tidal current turbine wake modelling and array arrangement optimization
    keyword : Tidal current energy, wake modelling, arrangement optimization
    2014.07~2016.03.
  • Environmental assessment on marine CCS
    keyword : Marine CCS, deep ocean storage, diffusion simulation, environmental assessment
    2010.04.
  • Study on High-Performance FSI Simulation Method
    keyword : Fluid-Structure Interaction, CFD, Weak coupling, Free surface impact
    2008.04.
  • Safety and Optimization Study on Large-Scale Floating Wind Farms in Waves
    keyword : Large-scale floating wind farm, Safety, Optimization, Wave impact
    2010.04.
  • Development of a New Ship Hull Form for Reducing CO2 Emission in a Seaway
    keyword : CO2 emission reduction, Energy-saving ship hull, CFD simulation
    2009.04.
  • Development of efficient CFD method for strongly nonlinear wave body interactions
    keyword : strongly nonlinear free surface surface motion, computational fluid dynamics, interface capturing method, wave impact
    2002.04Development of CFD simulation method for extremely nonlinear wave-body interaction Numerical simulation of floating body motion in rough seas is a challenging subject. The main difficulty arises from that the topology of free surface may be largely distorted or broken up, which makes it impossible to apply the conventional numerical method such as the potential-flow based method by BEM. In this study a new numerical method is developed. This method is a CIP based finite difference method which is not only able to handle the complex phenomena associated with the wave-body interaction, but also have relatively simple scheme in order to perform a three-dimensional time-dependent numerical simulations in an acceptable spatial and temporal resolution at a reasonable cost..
  • Numerical simulation of marine engine room fires
    keyword : engine room fire, CFD simulation, fire modeling
    2000.04~2004.03In this research, a CFD model has been developed for numerical simulation of marine fires..
  • Numerical simulation of low-concentration particle-gas multi-phase flows
    keyword : metallic fume, numerical simulation, low-concentration particle-gas multi-phase flow, working environment
    1998.04An high-efficiency ventilation System is very important for improving working environment in a fabrication shop of shipyard. The metallic fume generated from the welding or cutting process is expected to predict. In this research a numerical simulation method is developed and improved for this purpose. Now research on applying this method to prediction general air polution problems is ongoing. .
Current and Past Project
  • The final goal of this research is to establish an effective CFD analytical procedure for numerical simulation of a tidal current farm. A CFD method based on OpenFOAM will be developed for predicting the force coefficients and characterizing the wake of a tidal turbine. The experiment will also be carried out for validation of the CFD code.
  • As a part of large scale floating ocean renewable energy system project of RIAM, Kyushu University, a noval multi-purpose, cost effective semi-submersible type platform is developed with the coorperation of industries.
  • Fundemental researches are carried out on safety and environment assessment of ocean CCS, which is a project promoted by the "International Institute for Carbon-Neutral Energy Research (I2CNER)" of Kyushu University.
Academic Activities
Books
1. Masashi Kashiwagi, Changhong Hu and Makoto Sueyoshi, Numerical Computation Methods for Extremely Nonlinear Wave-Body Interactions,
Chapter 12 : Numerical Computation Methods for Extremely Nonlinear Wave-Body Interactions
, The world Scientific Publishing Co., in the series of Advances in Coastal and Ocean Engineering, Vol. 11, 2009.05.
Reports
1. CIP Method.
Papers
1. Cheng Liu, Changhong Hu, An adaptive multi-moment FVM approach for incompressible flows, Journal of Computational Physics, 10.1016/j.jcp.2018.01.006, 359, 239-262, 2018.04.
2. Cheng Liu, Changhong Hu, Adaptive THINC-GFM for compressible multi-medium flows, Journal of Computational Physics, 10.1016/j.jcp.2017.04.032, 342, 43-65, 2017.08, In this paper, a THINC (tangent of hyperbola for interface capturing) (Xiao F. et al., 2005) [26] coupled with GFM (Ghost Fluid Method) is proposed for numerical simulation of compressible multi-medium flows. The THINC scheme, which was first developed for incompressible flows, is applied for capturing the distorted material interface of compressible flows. The hybrid WENO (weighted essentially non-oscillatory) scheme with the blocked structured adaptive mesh refinement (AMR) method is implemented. Load balancing is considered in the parallel computing. Several well documented numerical tests are performed and the results show that the THINC scheme behaviors better in mass conservation. It is the first endeavor to implement THINC scheme with adaptive mesh for computing the compressible multiphase problems. The shock wave–helium bubble interaction test reveals that the present method is efficient in prediction of the deformed interface. The solver is further validated by shock wave impact SF6 interface with square, rectangle, forward and backward triangle shapes in which the wave positions and intersecting angles are compared quantitatively. Finally, the collapse of an air bubble under shock in water is simulated, global agreement with experimental and other numerical results are obtained..
3. Cheng Liu, Changhong Hu, A Second Order Ghost Fluid Method for an Interface Problem of the Poisson Equation, Communications in Computational Physics, 10.4208/cicp.OA-2016-0155, 22, 4, 965-996, 2017.10, A second order Ghost Fluid method is proposed for the treatment of interface problems of elliptic equations with discontinuous coefficients. By appropriate use of auxiliary virtual points, physical jump conditions are enforced at the interface. The signed distance function is used for the implicit description of irregular domain. With the additional unknowns, high order approximation considering the discontinuity can be built. To avoid the ill-conditioned matrix, the interpolation stencils are selected adaptively to balance the accuracy and the numerical stability. Additional equations containing the jump restrictions are assembled with the original discretized algebraic equations to form a new sparse linear system. Several Krylov iterative solvers are tested for the newly derived linear system. The results of a series of 1-D, 2-D tests show that the proposed method possesses second order accuracy in L norm. Besides, the method can be extended to the 3-D problems straightforwardly. Numerical results reveal the present method is highly efficient and robust in dealing with the interface problems of elliptic equations..
4. Cheng Liu, Changhong Hu, An immersed boundary solver for inviscid compressible flows, International Journal for Numerical Methods in Fluids, 10.1002/fld.4399, 85, 11, 619-640, 2017.12, In this paper, a simple and efficient immersed boundary (IB) method is developed for the numerical simulation of inviscid compressible Euler equations. We propose a method based on coordinate transformation to calculate the unknowns of ghost points. In the present study, the body-grid intercept points are used to build a complete bilinear (2-D)/trilinear (3-D) interpolation. A third-order weighted essentially nonoscillation scheme with a new reference smoothness indicator is proposed to improve the accuracy at the extrema and discontinuity region. The dynamic blocked structured adaptive mesh is used to enhance the computational efficiency. The parallel computation with loading balance is applied to save the computational cost for 3-D problems. Numerical tests show that the present method has second-order overall spatial accuracy. The double Mach reflection test indicates that the present IB method gives almost identical solution as that of the boundary-fitted method. The accuracy of the solver is further validated by subsonic and transonic flow past NACA2012 airfoil. Finally, the present IB method with adaptive mesh is validated by simulation of transonic flow past 3-D ONERA M6 Wing. Global agreement with experimental and other numerical results are obtained..
5. Cheng Liu, Changhong Hu, An adaptive multi-moment FVM approach for incompressible flows, Journal of Computational Physics, 10.1016/j.jcp.2018.01.006, 359, 239-262, 2018.04, In this study, a multi-moment finite volume method (FVM) based on block-structured adaptive Cartesian mesh is proposed for simulating incompressible flows. A conservative interpolation scheme following the idea of the constrained interpolation profile (CIP) method is proposed for the prolongation operation of the newly created mesh. A sharp immersed boundary (IB) method is used to model the immersed rigid body. A moving least squares (MLS) interpolation approach is applied for reconstruction of the velocity field around the solid surface. An efficient method for discretization of Laplacian operators on adaptive meshes is proposed. Numerical simulations on several test cases are carried out for validation of the proposed method. For the case of viscous flow past an impulsively started cylinder (Re=3000,9500), the computed surface vorticity coincides with the result of the body-fitted method. For the case of a fast pitching NACA 0015 airfoil at moderate Reynolds numbers (Re=10000,45000), the predicted drag coefficient (CD) and lift coefficient (CL) agree well with other numerical or experimental results. For 2D and 3D simulations of viscous flow past a pitching plate with prescribed motions (Re=5000,40000), the predicted CD, CL and CM (moment coefficient) are in good agreement with those obtained by other numerical methods..
6. Changhong Hu, Cheng Liu, Development of Cartesian Grid Method for Simulation of Violent Ship-Wave Interactions, Journal of Hydrodynamics, 10.1016/S1001-6058(16)60702-3, 28, 6, 1003-1010, 2016.12.
7. Xuhui Li, Fei Jiang, Changhong Hu, Analysis of the accuracy and pressure oscillation of the lattice Boltzmann method for fluid–solid interactions, Computers & Fluids, 10.1016/j.compfluid.2016.01.015, 129, 33-52, 2016.04, Investigations have been conducted to analyze the accuracy of the ghost fluid immersed boundary lattice Boltzmann method and the conventional interpolation/extrapolation bounce-back schemes. The intrinsic sources of pressure oscillation for numerical simulation of moving boundary flows have also been inves- tigated. An existing bilinear ghost fluid immersed boundary lattice Boltzmann method (BGFM) (Tiwari and Vanka, 2012) and a proposed quadratic ghost fluid immersed boundary lattice Boltzmann method (QGFM) have been compared with Guo’s second-order extrapolation bounce-back scheme (Guo et al.) and the linear and quadratic interpolation bounce-back scheme (LIBB, QIBB) (Bouzidi et al., 2001; Lalle- mand and Luo, 2003). To study the numerical pressure oscillations in the moving boundary problem, (i) three existing refilling techniques and one proposed refilling technique are compared; (ii) three col- lision models, including the single-relaxation-time model, the multiple-relaxation-time model and the two-relaxation-time model, are investigated; (iii) two force evaluation schemes, a Galilean invariant mo- mentum exchange method Wen et al. and a stress integration method Inamuro et al., are considered. The accuracy and the performance in pressure oscillation suppression for the studied numerical approaches are compared and discussed by five numerical examples: an eccentric cylinder flow, a Cylindrical Couette flow, an impulsively started cylinder in a channel, an oscillation cylinder in calm water and a particle suspension problem. The numerical results indicate that the accuracy of QGFM scheme is comparable to Guo’s scheme while the accuracy of BGFM is worse than both of them. The QIBB scheme shows the best performance in the space convergence accuracy among all the schemes. Selection of the collision model, refilling technique and force evaluation scheme affect the pressure oscillation phenomenon in moving boundary simulations remarkably..
8. Cheng Liu, Changhong Hu, An Efficient Immersed Boundary Treatment for Complex Moving Object, Journal of Computational Physics, 10.1016/j.jcp.2014.06.042, 274, 654-680, 2014.10.
9. Fei Jiang, Changhong Hu, Numerical Simulation of a Rising CO2 Droplet in the Initial Accelerating Stage by a Multiphase Lattice Boltzmann Method, Applied Ocean Research, 10.1016/j.apor.2013.06.005, 45, 0, 1-9, 2014.03, A multi-phase flow model which applies lattice Boltzmann method (LBM) is developed for numerical simulation
of the initial accelerating stage of a rising CO 2 droplet in the deep ocean. In the present LBM model, a
multiple-relaxation time (MRT) collision operator is adopted to increase the numerical stability, and a color
model is used to treat the two-phase fluid. A domain shift scheme is proposed to make the long distance
calculation available. The computation is accelerated by using the GPU computing and correspondent parallel
implementation techniques are developed. The proposed numerical model is first validated against several
benchmark problems: Laplace law test, binary Poiseuille flow problem and rise of a toluene droplet. Then
numerical simulation of a liquid CO 2 droplet rising from quiescence to its steady state is carried out and the
results are compared to a laboratory experiment. Excellent agreement is obtained on both terminal velocity
and variation of droplet shape..
10. Kangping Liao, Changhong Hu, A coupled FDM–FEM method for free surface flow interaction with thin elastic plate, Journal of Marine Science and Technology, 10.1007/s00773-012-0191-0, 18, 1, 1-11, 2013.03, A partitioned approach by the coupling finite difference method (FDM) and the finite element method
(FEM) is developed for simulating the interaction between free surface flow and a thin elastic plate. The FDM, in
which the constraint interpolation profile method is applied, is used for solving the flow field in a regular fixed
Cartesian grid, and the tangent of the hyperbola for interface capturing with the slope weighting scheme is used for
capturing free surface. The FEM is used for solving structural deformation of the thin plate. A conservative
momentum-exchange method, based on the immersed boundary method, is adopted to couple the FDM and the
FEM. Background grid resolution of the thin plate in a regular fixed Cartesian grid is important to the computational
accuracy by using this method. A virtual structure method is proposed to improve the background grid resolution
of the thin plate. Both of the flow solver and the structural solver are carefully tested and extensive validations
of the coupled FDM–FEM method are carried out on a benchmark experiment, a rolling tank sloshing with a thin
elastic plate..
11. Changhong Hu, Makoto Sueyoshi, Fei Jiang, Kiminori Shitashima,Tetsuo Yanagi, Rise and Dissolution Modeling of CO2 Droplet in the Ocean, Journal of Novel Carbon Resource Sciences, 7, 12-17, 2013.02, A numerical approach is proposed to study the behavior of a natural carbon dioxide (CO2) droplet leaked from the
seafloor. Motion and deformation of the droplet at the initial stage are simulated by a lattice Boltzmann multi-phase
method to obtain the terminal velocity. The whole process of droplet rise and dissolution is modeled by a simplified
analytical method. The in-situ experiment case on a natural CO2 droplet at the Okinawa Trough (Shitashima, et al.1))
is studied by using the proposed numerical model. Numerical experiments show strong dependency between the
terminal velocity and the droplet density. The phenomena obtained in the on-sea observation are discussed by the
present numerical study..
12. Xizeng Zhao, Changhong Hu, Numerical and experimental study on a 2-D floating body under extreme wave conditions, Applied Ocean Research, 10.1016/j.apor.2012.01.001, 35, 1-13, 2012.03, This paper presents further developments of a constrained interpolation profile (CIP)-based Cartesian grid method (Hu et al. [29]) to model nonlinear interactions between extreme waves and a floating body, which is validated against to a newly performed experiment. In the experiment, three kinds of waves (regular wave, focused wave and combined regular and focused wave) are generated and a box-shaped floating body with a superstructure is used. Validation computations on the experiment are performed by the improved CIP-based Cartesian grid method, in which the THINC/WLIC scheme (THINC: tangent of hyperbola for interface capturing; WLIC: Weighed line interface calculation), is used for interface capturing. The highly nonlinear wave-body interactions, including large amplitude body motions and water-on-deck are numerically investigated through implementation of focused wave input to the CIP-based method. Computations are compared with experimental results and good agreement is achieved. The effects of the water-on-deck phenomena and different input focus positions on the body response are also dealt with in the research..
13. Fei JIANG, Changhong Hu, Application of Lattice Boltzmann Method for Simulation of Turbulent Diffusion from a CO2 Lake in Deep Ocean, Journal of Novel Carbon Resource Sciences, 5, 10-18, 2012.02.
14. Changhong Hu, Makoto Sueyoshi,Masashi Kashiwagi, Numerical Simulation of Strongly Nonlinear Wave-Ship Interaction by CIP/Cartesian Grid Method, Int. Journal of Offshore and Polar Engineering, 20, 2, 81-87, 2010.06.
15. Changhong Hu, Makoto Sueyoshi , Ryuji Miyake, Tingyao Zhu, Computation of Fully Nonlinear Wave Loads on a Large Container Ship by CIP based Cartesian Grid Method, Proceedings of the ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2010-20286, 2010.06.
16. Changhong Hu, Masashi Kashiwagi, Two-dimensional numerical simulation and experiment on strongly nonlinear wave–body interactions , Journal of Marine Science and Technology, 10.1007/s00773-008-0031-4, 14, 2, 200-213, 2009.06.
17. Changhong Hu, Masashi Kashiwagi, and Makoto Sueyoshi, Improvement towards High-Resolution Computation on Strongly Nonlinear Wave-Induced Motions of an Actual Ship, Proc. of 27th Symposium on Naval Hydrodynamics, pp. 525-534, 2008.10.
18. Changhong Hu and Masashi Kashiwagi, Numerical and Experimental Studies on Three-Dimensional Water on Deck with a Modified Wigley Model, Proc. 9th Int. Conf. on Numerical Ship Hydrodynamics, Vol 1, pp.159-169, 2007.08.
19. Zdravko Kishev, Changhong Hu and Masashi Kashiwagi, Numerical simulation of violent sloshing by a CIP-based method, Journal of Marine Science and Technology, V. 11, pp.111-122, 2006.06.
20. Hu, CH, Kashiwagi, M, Kishev, Z, Sueyoshi, M and Faltinsen, O., Application of CIP Method for Strongly Nonlinear Marine Hydrodynamics, Ship Technology Research, V.53, No. 2, pp 74-87, 2006.06.
21. Changhong Hu, Odd Faltinsen and Masashi Kashiwagi, 3-D Numerical Simulation of Freely Moving Floating Body by CIP Method, Proc. 15th International Offshore and Polar Engineering Conference, 674-679, Vol. 4, pp.674-679, 2005.06.
22. Changhong Hu and Masashi Kashiwagi, A CIP-Based Method for Numerical Simulations of Violent Free Surface Flows, Journal of Marine Science and Technology, 10.1007/s00773-004-0180-z, 9, 4, 143-157, Vol.9, No.4, pp. 143-157, 2004.12.
23. Changhong Hu, Masashi Kashiwagi and Zdravko Kishev, Numerical Simulation of Violent Sloshing by CIP Method, Proc. 19th International Workshop on Water Waves and Floating Bodies, pp.67-70, 2004.03.
24. Changhong Hu and Nobuyoshi Fukuchi, A Field Modeling Approach to Prediction of Hot Gas Movement Induced by Marine Compartment Fires, International Journal of Offshore and Polar Engineering, 13, 4, 249-253, Vol. 13, No. 4, pp.249-253, 2003.12.
25. Changhong Hu and Masashi Kashiwagi, Development of CFD Simulation Method for Extreme Wave-Body Interactions, Proceedings of the 8th International Conference on Numerical Ship Hydrodynamics, Vol.2, pp. 50-57, 2003.09.
26. Changhong Hu and Masashi Kashiwagi, Numerical Simulation of Non-Linear Free Surface Wave Generation by CIP Method and Its Applications, Proceedings of the 13th International Offshore and Polar Engineering Conference, 294-299, Vol. 3, pp. 294-299, 2003.05.
27. Changhong Hu and Masashi Kashiwagi, A CIP Based Numerical Simulation Method for Extreme Wave-Body Interaction, Proc. 18th International Workshop on Water Waves and Floating Bodies, 2003.04.
Presentations
1. Changhong Hu, Makoto Sueyoshi, Chen, Liu, Yusaku Kyozuka, Yuji Ohya, Numerical and Experimental Study on a Floating Platform for Offshore Renewable Energy, the ASME 2012 32th International Conference on Ocean, Offshore and Arctic Engineering , 2013.06.
2. Development of CIP Based Cartesian Grid Method and Its Application to Strongly Nonlinear Wave-Body Interactions.
Membership in Academic Society
  • The International Society of Offshore and Polar Engineers
  • The Japan Society of Naval Architects and Ocean Engineers
  • The Japan Society of Mechanical Engineers
Educational
Educational Activities
From 1995 to 2002, as an assistant professor of Kyushu University, involved in education activities.
From 2002, as an associate professor, and from 2014 as a professor of Kyushu University, in charge of a coorperative laboratory in the Department of Earth System Science and Technology, Interdisciplinary Graduate School of Engineering Sciences. Lectures for graduated students are as follows.

Master Course
(1) Earth system fluid dynamics 1 (shear, 2 credits)
(2) An Introduction to CFD (2 credits)
(3) Dynamics of ocean systems Seminar (4 credits)
(4) Practical data processing (common, shear, 2 credits)

Doctor Course
(1) Special lecture on ocean systems dynamics (4 credits)
(2) Tutorials on PhD thesis (2 credits)
(3) Tutorials on interdisciplinary engineering sciences (Environment) (shear, 2 credits)
Social
Professional and Outreach Activities
Academic and industry collaboration

2003-2007 Development of CFD for strongly nonlinear wave-body interactions, (with Akishima Laboratories INC.)
2008-2013 CFD development for predicting ship hydrodynamics with the consideration of hull form above waterline, (with Mitrui Engineering and Shipbuilding Co., LtD)
2009-2010 CFD development for Prediction of wave loads in bow seas, (with ClassNK)
2011-2013 Study on safety assessment method for floating wind turbine, (with ClassNK)
2012-2015 Development of novel ocean platform for offshore wind, (with Oshima Shipbuilding, Shikurushima Dock, Tsuneishi holdings)
2015-present Development of TLP floating tower for offshore power transmission in the air, (with Furukawa Electric, Toray, Akishima Laboratory, Japan Radio)

International collaboration research
2009-2010 Numerical simulation on violent tank sloshing, (with Seoul National University, Korea)
2012-2014 Experimental and numerical study on tidal energy converters, (with Harbin Engineering University, China)
2015-present Delopment of high performance CFD method for FOWT, (with Shanghai Jiao Tong University, China).