Kyushu University Academic Staff Educational and Research Activities Database
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Takanori Uchida Last modified date:2018.05.25



Graduate School


E-Mail
Homepage
http://www.riam.kyushu-u.ac.jp/windeng/
Introduction of my research .
Phone
092-583-7776
Fax
092-583-7779
Academic Degree
Dr. Eng
Field of Specialization
Wind engineering, Environmental fluid dynamics, CFD, EFD
Research
Research Interests
  • Development of the Non-Stationary and Non-Linear Wind Synopsis Simulator, RIAM-COMPACT
    keyword : LES, RIAM-COMPACT, Wind Energy Utilization, Atmospheric Environmental Assessment, Airflow over Complex Terrain and Buildings, Gas Diffusion, Bluff-Body Aerodyanmics
    2000.01.
  • Numerical Simulation and Wind Tunnel Experiment of Atmospheric Stratified Flows under Various Stabilities
    keyword : Atmospheric Stratified Flow, Atmospheric Boundary Layer, Numerical Simulation (DNS, LES), Wind Tunnel Experiment
    2000.01.
  • Basic Research on Numerical Simulation Method Based on Finite-Difference Method (FDM)
    keyword : Numerical Simulation Method, Finite-Difference Method (FDM), DNS, LES
    2000.01.
Academic Activities
Papers
1. Takanori Uchida, Reproducibility of Complex Turbulent Flow Using Commercially-Available CFD Software
―Report 1: For the Case of a Three-Dimensional Isolated-Hill With Steep Slopes―, Reports of Research Institute for Applied Mechanics, Kyushu University, 150, 47-59, 2016.03.
2. Takanori Uchida, Reproducibility of Complex Turbulent Flow Using Commercially-Available CFD Software
―Report 2: For the Case of a Two-Dimensional Ridge With Steep Slopes―, Reports of Research Institute for Applied Mechanics, Kyushu University, 150, 67-70, 2016.03.
3. Takanori Uchida, Reproducibility of Complex Turbulent Flow Using Commercially-Available CFD Software
―Report 3: For the Case of a Three-dimensional Cube―, Reports of Research Institute for Applied Mechanics, Kyushu University, 150, 71-83, 2016.03.
4. Takanori Uchida, Fumihito Watanabe, Shin Mikami, Analysis of the Airflow Field around a Steep, Three-dimensional Isolated Hill with Commercially Available CFD Software, Reports of Research Institute for Applied Mechanics, Kyushu University, 149, 91-98, 2015.09.
5. Fumihito Watanabe, Takanori Uchida, Micro-siting of Wind Turbine in Complex Terrain:Simplified Fatigue Life Prediction of Main Bearing in Direct Drive Wind Turbines, WIND ENGINEERING, http://dx.doi.org/10.1260/0309-524X.39.4.349, 39, 4, 349-368, 2015.07, In Japan, 1,516 wind turbine accidents have been recorded between year 2004 and 2012, and 84% of them were for turbines in complex terrains. The longest downtime was associated with damage to main shafts or bearings with an average downtime of 5.7 months. Careful micro-siting in complex terrains can prevent these accidents from happening.

The objective of the paper is to provide an intermediate step that allows consultants, developers, and wind farm owners to further evaluate micro-siting of wind turbines in complex terrains, prior to load simulations by manufacturers. The author developed a simplified method to predict fatigue life of a main rear bearing in direct drive wind turbines. The method uses hub-height 10 minutes wind data as an input. The validation with an actual accident showed practically good agreement of 12.0 years of the predicted life against 12.7 years of the actual life. The method was also applied to quantify the effect of a curtailment. The proposed curtailment increased the predicted life to 35.5 years with a relatively small range of wind speed at a direction of only 1 % frequency distribution.

With the proposed method, it is possible to layout turbines where fatigue life of a main rear bearing is longer than its design life. The method can also be applied to existing turbines in order to spot turbines that require careful maintenance, and to consider an installation of condition monitoring system on a bearing..
6. Takanori Uchida, An Examination of the Taikoyama Wind Farm Nacelle Separation Accident Using a CFD Approach, Reports of Research Institute for Applied Mechanics, Kyushu University, 148.0, 15.0-24.0, 2015.03, Because a significant portion of the topography of Japan is characterized by steep, complex terrain, which results in a complex spatial distribution of wind speed, great care is necessary for selecting a site for the construction of wind turbines. We have developed a computational fluid dynamics (CFD) model for unsteady flow called Research Institute for Applied Mechanics, Kyushu University, COMputational Prediction of Airflow over Complex Terrain (RIAM-COMPACT®). The RIAM-COMPACT® CFD model is based on the large-eddy simulation (LES) technique. In this paper, a numerical wind simulation for the Taikoyama Wind Farm is performed using high-resolution terrain elevation data. The results suggest that all six wind turbines at the Taikoyama Wind Farm are subject to significant influence from separated flow (terrain-induced turbulence) which is generated due to the topographical irregularities in the vicinity of the wind turbines. A proposal has been also made on reconstruction of the wind farm..
7. Takanori Uchida, Validation Testing of the Prediction Accuracy of the Numerical Wind Synopsis Prediction Technique RIAM-COMPACT for the Case of the Bolund Experiment-Comparison against a Wind-Tunnel Experiment-, Reports of Research Institute for Applied Mechanics, Kyushu University, 147, 7-14, 2014.09.
8. Takanori UCHIDA, Takashi MARUYAMA, Tetsuya TAKEMI, Yuichiro OKU, Yuji OHYA and Graham Li , Proposal of Designed Wind Speed Evaluation Technique in WTG Installation Point by Using the Meteorological Model and CFD Model
, 九州大学応用力学研究所所報, 第141号, pp.1-12, 2011.10.
9. Takanori UCHIDA, Takashi MARUYAMA, Hirohiko ISHIKAWA, Masaru ZAKO and Akira DEGUCHI , Investigation of the Causes of Wind Turbine Blade Damage at Shiratakiyama Wind Farm in Japan-A Computer Simulation Based Approach-, 九州大学応用力学研究所所報, 第141号, pp.13-25, 2011.10.
10. 内田孝紀,大屋裕二, LES技術を用いたウインドファーム風況診断―熊本県阿蘇車帰風力発電所を例として―, 土木学会論文集A2(応用力学)Vol.67 特集号, 2011.09.
11. Takanori Uchida, Takashi Maruyama and Yuji Ohya, New Evaluation Technique for WTG Design Wind Speed using a CFD-model-based Unsteady Flow Simulation with Wind Direction Changes, Modelling and Simulation in Engineering, Volume 2011 (2011), 2011.03.
12. Takanori Uchida, Yuji Ohya and Kenichiro Sugitani, Comparisons Between The Wake Of A Wind Turbine Generator Operated At Optimal Tip Speed Ratio And The Wake Of A Stationary Disk, Modelling and Simulation in Engineering, Volume 2011 (2011), 2011.03.
13. Takanori Uchida and Yuji Ohya, Latest Developments in Numerical Wind Synopsis Prediction Using the RIAM-COMPACT® CFD Model—Design Wind Speed Evaluation and Wind Risk (Terrain-Induced Turbulence) Diagnostics in Japan, Energies, 4(3), pp.458-474, 2011.03.
14. Takanori UCHIDA, Yuji OHYA, Challenge to Huge Computation of Airflow around Urban Area by using RIAM-COMPACT® CFD Model, Proceedings of EAEP2010/The 4th International Symposium on the Asian Environmental Problems, pp.191-194, 2010.09.
15. Hirotaka HANO, Takanori UCHIDA, Yuji OHYA, Wake Structure Behind Wind Turbine Generator in Turbulent Boundary Layer, Proceedings of EAEP2010/The 4th International Symposium on the Asian Environmental Problems, pp.195-200, 2010.09.
16. Takanori Uchida and Yuji Ohya, Large-Eddy Simulation of Topography-Induced Turbulence around WTG by using the RIAM-COMPACT® CFD Model, Proceedings of RENEWABLE ENERGY 2010 (RE2010), 2010.06.
17. Takanori Uchida and Yuji Ohya, HIGH RESOLUTION LES OF TURBULENT AIRFLOW OVER COMPLEX TERRAIN, Proceedings of Seventh Asia-Pacific Conference on Wind Engineering (APCWE-VII), pp.405-408, 2009.11.
18. Tomohiro Hara, Yuji Ohya, Takanori Uchida, Ryohji Ohba, Wind-Tunnel and Numerical Simulations of the Coastal Thermal Internal Boundary Layer, Boundary-Layer Meteorology, Vol.130, pp.365-381, 2009.02.
19. Takanori Uchida, Yuji Ohya, The wind risk management in the wind farm by using the RIAM-COMPACT CFD code, Proceedings of China Wind Power 2008 & Global Wind Power 2008, 2008.10.
20. Takanori Uchida, Yuji Ohya, Numerical Simulation of Airflow around Urban Area by using the RIAM-COMPACT CFD Model, Proceedings of Sino-Japan International Symposium on The East Asian Environmental Problems (EAEP2008), pp.51-53, 2008.08.
21. Yuji Ohya, Takanori Uchida, Laboratory and numerical studies of the atmospheric stable boundary layers, Journal of Wind Engineering & Industrial Aerodynamics, Vol.96, pp.2150-2160, 2008.07.
22. Takanori Uchida and Yuji Ohya, Micro-siting Technique for Wind Turbine Generators by Using Large-Eddy Simulation, Journal of Wind Engineering & Industrial Aerodynamics, Vol.96, pp.2121-2138, 2008.07, 風力業界で未解決課題であった風車に対する風の乱れ(ウィンドリスク)に対して,NEDO技術開発機構の産業技術研究助成事業(若手研究グラント)に採択され,研究代表者として3年間の研究開発を実施した.本研究を通じ,先端的数値風況予測モデル「RIAM-COMPACT®(リアムコンパクト)」を駆使し,世界で初めてウィンドリスクの存在を視覚的に特定することに成功し,その力学的機構を解明した.一連の成果に対し,2010年科学技術分野の文部科学大臣表彰・若手科学者賞を受賞した..
23. T.Uchida and Y.Ohya, Verification of the Prediction Accuracy of Annual Energy Output at Noma Wind Park by the Non-Stationary and Non-Linear Wind Synopsis Simulator, RIAM-COMPACT, Journal of Fluid Science and Technology, Vol.3, No.3, pp.344-358, 2008.06.
24. Yuji Ohya, Reina Nakamura, Takanori Uchida, Intermittent Bursting of Turbulence in a Stable Boundary Layer with Low-Level Jet,Boundary-Layer Meteorology, Boundary-Layer Meteorology, vol.26, No.3, pp.349-363, 2008.01.
25. Takanori Uchida, High Resolution LES of Airflow over Complex Terrain, Proceedings of APCOM'07-EPMESC XI, 2007.12.
26. Takanori Uchida, Yuji Ohya, Diagnosis of Airflow Characteristics in Wind Farm by Using the Unsteady Numerical Model RIAM-COMPACT, Proceedings of Renewable Energy 2006, 2006.10.
27. T.Uchida and Y.Ohya, Application of LES Technique to Diagnosis of Wind Farm by Using High Resolution Elevation Data, JSME International Journal, 「Environmental Flows」, Series B, Vol.49, No.3, pp.567-575, 2006.09.
28. Takanori Uchida, Yuji Ohya, Numerical simulation of atmospheric flow over complex terrain, Journal of Industrial Aerodynamics, 10.1016/S0167-6105(99)00024-0, 81, 283-293, 1999.05, In order to develop an overall efficient and accurate method of simulating an unsteady three-dimensional atmospheric flow over topography, we examined two grid systems and corresponding variable arrangements: one is a body-fitted coordinate (BFC) grid system based on a collocated variable arrangement; the other is an orthogonal grid system based on a staggered variable arrangement. Using these codes, we calculated the wind system over topography such as an isolated hill and real complex terrain. Both codes remarkably removed the numerical difficulties such as the convergence of the SOR method in solving the pressure Poisson equation, resulting in numerical results with much higher accuracy. Despite the differences in the grid system and in variable arrangement, no significant differences in the flow pattern between the both numerical results were found. Compared with the previous studies, the numerical results obtained are very satisfactory in the sense that overall characteristic flows are successfully simulated irrespective of the simulation codes..
29. Takanori Uchida, Y. Ohya, A numerical study of stably stratified flows over a two-dimensional hill - Part I. Free-slip condition on the ground, Journal of Industrial Aerodynamics, https://doi.org/10.1016/S0167-6105(97)00096-2, 67-68, 493-506, 1997.01, Stably stratified flows over a two-dimensional hill in a channel of finite depth are analyzed numerically by using a newly-developed multi-directional finite-difference method at a Reynolds number Re = 2000. To simplify the phenomena occurring in the flow around the hill, the free-slip condition for the velocity is assumed on the ground, and the nonslip condition is imposed only on the hill surface. Attention is focused on the unsteadiness in the flow around the hill for the cases of K( = NH/πU) > 1 where N and U are the buoyancy frequency and free-stream velocity and H is the domain depth. The flow unsteadiness is discussed, being associated with shedding of the upstream advancing columnar disturbance..
Works, Software and Database
1. .
Membership in Academic Society
  • Japan Society of Fluid Mechanics
  • Japan Association for Wind Engineering
  • Japan Society of Mechanical Engineers
  • Japan Wind Energy Association