磁気対流

2001 年度 実績報告書

• 研究課題/領域番号: 10211207
• 研究機関: 九州大学
• 研究代表者: 尾添 紘之 九州大学, 機能物質科学研究所, 教授 (10033242)
• 研究分担者: 赤松 正人 秋田県立大学, システム科学技術学部, 助手 (40315320) ; 岩本 光生 大分大学, 工学部, 講師 (80232718) ; 田川 俊夫 九州大学, 機能物質科学研究所, 助手 (90294983)
• キーワード: 磁気対流 / ローレンツ力 / チョクラルスキー法 / ゼーベック効果 / 磁化力対流 / 結晶成長 / 酸素ガス / 超伝導電磁石

研究概要

鉄鋼の連鋳プロセスや単結晶成長での磁場利用は鉄鋼の高品位化や、単結晶の高純度化をめざして今後益々多用化される機運にある。しかし、これらの理論的裏付けが不十分にみえる。本研究では、各種磁場対流現象と動作流体の流動現象の定量的把握とその制御を試みた。
電子集積回路の原料シリコン融液は、低プラントル数流体で、本質的に振動対流をなすことが知られている。そのため、単結晶中に成長縞と呼ばれる結晶構造や不純物濃度などの不均一部分が内蔵され、その後の製造過程において、歩留まり低下を与えている。そこで、この原因となる原料融液の熱流動状況の把握と制御をめざした。まず、チョクラルスキー単結晶成長融液の熱流動特性を解析した。対象とした系は、高さH,直径1.25H,結晶棒直径0.625Hでルツボは高温に加熱され、結晶棒は低温に保たれ、自由表面からは輻射冷却されるものとする。融液の非定常二次元流動は保存方程式でモデル化される。流体はインジウムアンチモンの融液である。計算の結果、軸対称な境界条件を持つ円筒容器内に一つの大きなロールが存在することが予測された。さらに本系に、水平方向に一様な磁場が印加された場合、等温線は軸対称な境界条件にも拘わらず、磁場に直交する断面から液面に流れがあふれて、磁場に平行な断面に液が流下している。底部近くではこれが逆転することを見い出した。これは先にkajigayaらにより報告された楕円柱型GaAs単結晶の成因を説明するものとなった。
次に超伝導磁場下における鉛直円管内の酸素の対流拡散現象について調べた。即ち、超伝導電磁石のボア内に50mmφx600mmの円筒容器を入れ、酸素を満たし、その後、円筒容器の上下端を大気に開放し、円筒容器中央部で酸素ガス濃度の経時変化を測定した。その結果、磁場がないときは、酸素濃度は200秒で、外気と同じ濃度に急減した。一方、10T,12Tではほぼ拡散速度で減少し2000秒後に30%位に降下した。ついでこの現象の数値解析を行った。その結果、中央高さにおける酸素濃度の減少特性は、実験結果と極めて類似した特性を示し我々の用いたモデル方程式の正しさを証するものとなった。
その他、チョクラルスキー結晶成長におけるカスプ型磁場効果、回転磁場効果、ゼーベック効果、磁化力による擬似無重力空間の創成と解析など、多数の成果が得られた。

研究成果

• [文献書誌] Masato Akamatsu et al.: "Numerical calculation of natural and mixed convection in a Czochralski crucible under transverse magnetic fields"Heat Transfer 1998, Proc. of 11th IHTC, Kyongju. 3. 239-244 (1998)
• [文献書誌] Yoo Cheol Won et al.: "Transient three-dimensional numerical computation for silicon melt under a cusp-shaped magnetic field"5th ASME/JSME Joint Thermal Eng. Conf., San Diego, California. No.6459 (1999)
• [文献書誌] Toshio Tagawa et al.: "Natural convection of liquid metal in a cube with uniform flux heating from a side wall under horizontal magnetic fields"5th ASME/JSME Joint Thermal Eng. Conf., San Diego, California. No.6462 (1999)
• [文献書誌] Masato Akamatsu et al.: "One-sided natural and mixed convection computed for liquid metal in a Czochralski configuration"5th ASME/JSME Joint Thermal Eng. Conf., San Diego, California. No.6463 (1999)
• [文献書誌] Hiroyuki Ozoe: "Numerical computations for Czochralski convection"Japan-France Cooperative Science Program Seminar on New Aspects of Electromagnetic Processing of Materials, Nikko. 82-85 (1999)
• [文献書誌] 尾添紘之 他: "熱対流における静磁場の影響"電磁力を利用した材料プロセッシングの新展開 (日本鉄鋼協会). 203-214 (1999)
• [文献書誌] 尾添紘之 他: "Cz結晶成長融液へのZ軸磁場印加効果"電磁力を利用した材料プロセッシングの新展開 (日本鉄鋼協会). 221-226 (1999)
• [文献書誌] Masayuki Kaneda et al.: "Thermoelectric effect on natural convection of liquid metal"12th Taejon/Chungnam-Kyushu Symp., Taejon. 81-82 (1999)
• [文献書誌] Toshio Tagawa et al.: "Influence of magnetizing force on natural convection"Int. Symp. on New Magneto-Science "99, Omiya. 332-338 (1999)
• [文献書誌] Masayuki Kaneda et al.: "Seebeck convection of liquid metal in a cube under various directions of the magnetic field"Int. Symp. on New Magneto-Science "99, Omiya. 339-334 (1999)
• [文献書誌] Hiroyuki Ozoe: "Melt stirring effect of a weak magnetic field on crystal growth"Progress in Crystal Growth and Characterization of Materials, The role of magnetic fields in crystal growth (Edited by K. W. Benz). 38. 239-259 (1999)
• [文献書誌] Yoo Cheol Won et al.: "Transient three-dimensional flow characteristics of Si melt in a cusp-shaped magnetic field"Numerical Heat Transfer, Part A. 36. 551-561 (1999)
• [文献書誌] Mitsuyuki Hatanaka et al.: "Numerical computation of oscillatory Rayleigh-Benard natural convection of gallium in a rectangular region with aspect ratios equaL to five"Proc. Symposium on Energy Engineering in the 21 Century(SEE 2000), Hong Kong. 1. 288-294 (2000)
• [文献書誌] Masayuki Kaneda et al.: "Natural convection of liquid metal with and without Seebeck effect"Proc. Symposium on Energy Engineering in the 21 Century (SEE 2000), Hong Kong. 1. 302-309 (2000)
• [文献書誌] 金田昌之 他: "液体金属の自然対流に対する熱電効果の影響"化学工学シンポジウムシリーズ72,移動現象および化学装置の開発に関する数値シミュレーション技術. 72. 72-77 (2000)
• [文献書誌] Hiroyuki Ozoe: "Numerical computation of natural and mixed convection of liquid metal in a cubical or cylindrical enclosure with a uniform magnetic field (Key Note Lecture)"The 3rd Int. Symp. on Electromagnetic Processing of Materials(EPM2000), Nagoya, Japan. 73-78 (2000)
• [文献書誌] Masayuki Kaneda et al.: "Numerical computation of natural convection of liquid metal in a cubic enclosure on the effect of Seebeck convection"The 3rd Int. Symp. on Electromagnetic Processing of Materials(EPM2000), Nagoya, Japan. 165-170 (2000)
• [文献書誌] Hiroyuki Ozoe et al.: "Application of various magnetic fields for the melt in a Czochralski crystal growing system"20th Int.Congress of Theoretical and Applied Mechanics (ICTAM 2000), Chicago. 191,OO2 (2000)
• [文献書誌] Toshio Tagawa et al.: "Buoyant flow in long vertical enclosures under the presence of horizontal magnetic field"20th Int.Congress of Theoretical and Applied Mechanics (ICTAM 2000), Chicago. 199,PO1 (2000)
• [文献書誌] Mitsuo Iwamoto et al.: "Numerical computation of non-axisymmetric convection in the melt of Czochralski crystal growth"The 1st Asian Conference on Crystal Growth and Crystal Technology (CGCT-1, 2000), Japan. T-D-03 (2000)
• [文献書誌] Janusz S.Szmyd et al.: "An analysis of natural convection with radiation from the free surface of the fluid in a vertical cylinder"JSME International Journal, Fluids and Thermal Engineering, Series B. 43. 679-685 (2000)
• [文献書誌] Mitsuo Iwamoto et al.: "Experimental study of natural and forced convection of liquid metal under a rotational magnetic field"The 4th JSME-KSME Thermal Eng. Conf., Kobe. 3. 225-228 (2000)
• [文献書誌] Masato Akamatsu et al.: "Convectional control in silicon melts under a magnetic field"The 4th JSME-KSME Thermal Eng. Conf., Kobe. 3. 229-234 (2000)
• [文献書誌] Riki Noda et al.: "Control of natural convection of air in a cubic enclosure under magnetizing force of one coil"13th Symp. on Chem. Eng. Kyushu -Taejon/Chungnam. 33-34 (2000)
• [文献書誌] Syou Maki et al.: "Rayleigh-Benard convection of air within a thin cylindrical enclosure in the presence of a high magnetic field"13th Symp. on Chem. Eng. Kyushu -Taejon/Chungnam. 37-38 (2000)
• [文献書誌] 金田昌之 他: "立方体容器内の空気の熱伝導に対する磁化力効果"Symposium on New Magneto-Science 2000, Proceedings of the Fourth Meeting, Omiya. 123-128 (2000)
• [文献書誌] 田川俊夫 他: "開放端パイプ内の酸素ガスの対流拡散現象への磁化力効果"Symposium on New Magneto-Science 2000, Proceedings of the Fourth Meeting, Omiya. 129-134 (2000)
• [文献書誌] 田川俊夫 他: "超伝導磁場下における鉛直円管内の酸素の対流拡散現象"化学工学シンポジウムシリーズ75 化学装置における種々の流体の流動状態に関する数値解析と可視化技術. 75. 88-95 (2001)
• [文献書誌] 田川俊夫 他: "超伝導磁場下における鉛直円管内の空気の浮力流れの過渡的特性"化学工学シンポジウムシリーズ75 化学装置における種々の流体の流動状態に関する数値解析と可視化技術. 75. 96-104 (2001)
• [文献書誌] Hiroyuki Ozoe: "Natural and mixed convection of liquid metals in magnetic field (Key Note Lecture)"2nd International Symposium on Advances in Computational Heat Transfer, Australia. 1. 139-153 (2001)
• [文献書誌] Toshio Tagawa et al.: "Convective and diffusive phenomena of air in a vertical cylinder under a strong magnetic field"2nd International Symposium on Advances in Computational Heat Transfer, Australia. 2. 777-783 (2001)
• [文献書誌] Syou Maki et al.: "Natural convection of air in a shallow cylinder of the aspect ratio three under a high magnetic field"2nd International Symposium on Advances in Computational Heat Transfer, Australia. 2. 851-857 (2001)
• [文献書誌] Masayuki Kaneda et al.: "Seebeck effect convection of liquid metal in an enclosure with wall Seebeck coefficient"2nd International Symposium on Advances in Computational Heat Transfer, Australia. 2. 891-896 (2001)
• [文献書誌] Janusz S.Szmyd et al.: "Three-dimensional numerical simulation of spoke pattern in Bridgman top seeding convection"2nd International Symposium on Advances in Computational Heat Transfer, Australia. 2. 929-936 (2001)
• [文献書誌] Masato Akamatsu et al.: "Convectional control in silicon melts under a rotating magnetic field"2nd International Symposium on Advances in Computational Heat Transfer., Australia. 2. 1113-1120 (2001)
• [文献書誌] Ryoji Shigemitsu et al.: "Combined effect of the magnetizing force and the Rayleigh number on the natural convection of air in a cubic enclosure"XXIX Summer School "Advanced Problems in Mechanics" St. Petersburg (Repino), Russia. (2001)
• [文献書誌] Toshio Tagawa et al.: "Numerical computation of natural convection of liquid metal in a cubic enclosure in the presence of a uniform magnetic field with theoretical treatment for Hartmann layer"III France-Japan Seminar on Electromagnetic processing of materials in the III Milennium, Chanonix, France. 41-44 (2001)
• [文献書誌] Hiroyuki Ozoe et al.: "Convection of air under magnetizing and gravitational forces in a cubic enclosure heated from a vertical wall and cooled from an opposing wall"III France-Japan Seminar on Electromagnetic processing of materials in the III Milennium, Chanonix, France. 77-80 (2001)
• [文献書誌] Masato Akamatsu et al.: "Elliptic temperature contours under a transverse magnetic field computed for a Czochralski melt"International Journal of Heat and Mass Transfer. 44. 3253-3264 (2001)
• [文献書誌] 牧祥 他: "磁化力による加速度増強下での空気のレイリー・ベナール対流の数値計算"九州大学機能物質科学研究所報告. 15. 25-30 (2001)
• [文献書誌] Toshio Tagawa et al.: "Transient characteristics of convection and diffusion of oxygen gas in an open vertical cylinder under magnetizing and gravitational forces"Chemical Engineering Science. 56. 4217-4223 (2001)
• [文献書誌] Masato Akamatsu et al.: "Two-dimensional numerical computation for natural convection of air in a vertical cylindrical container under both gravitational and magnetizing forces"Proceedings of the First International Symposium on Advanced Fluid Information, Sendai, Japan. 318-323 (2001)
• [文献書誌] Yoo Cheol Won et al.: "Transient three-dimensional numerical computation for unsteady oxygen concentration in a silicon melt during a Czochralski process under a cusp-shaped magnetic field"Journal of Crystal Growth. 233. 622-630 (2001)
• [文献書誌] Masato Akamatsu et al.: "Behavior of air in a vertical cylindrical container with the temperature boundary condition of the floating zone crystal growth process under a strong magnetic field"2001 IAMS International Seminar on Materials for Use in Lithium Batteries and Transport Phenomena in Material Processing, Kyushu Univ.. 133-142 (2001)
• [文献書誌] Toshio Tagawa et al.: "Effect of magnetic field on various transport phenomena"2001 IAMS International Seminar on Materials for Use in Lithium Batteries and Transport Phenomena in Material Processing, Kyushu Univ.. 143-150 (2001)
• [文献書誌] Chang Ho Lee et al.: "Numerical analysis of fluid flows in Czochralski crystal growth under a strong cusp-shaped magnetic field"The 14th Symp. on Chem. Eng. Kyushu -Taejon/Chungnam (Korea) Kyushu (Japan). 163-164 (2001)
• [文献書誌] Shinichi Nishida et al.: "Influence of magnetizing force on natural convection of air heated from a part of a vertical tube"The 14th Symp. on Chem. Eng. Kyushu -Taejon/Chungnam (Korea) Kyushu (Japan). 183-184 (2001)
• [文献書誌] Gen Tomita et al.: "Effect of a magnetizing force for heat transfer of air in a cylindrical pipe in a micro gravity field"The 14th Symp. on Chem. Eng. Kyushu -Taejon/Chungnam (Korea) Kyushu (Japan). 199-200 (2001)
• [文献書誌] Seiji Taniguchi et al.: "Effect of a magnetizing force for Combustion model in a vertical cylindrical pipe"The 14th Symp. on Chem. Eng. Kyushu -Taejon/Chungnam (Korea) Kyushu (Japan). 201-202 (2001)
• [文献書誌] Toshio Tagawa et al.: "Magnetizing force modeled and numerically solved for natural convection of air in a cubic enclosure : Effect of the direction of the magnetic field"International Journal of Heat and Mass Transfer. 45. 267-277 (2002)
• [文献書誌] Masayuki Kaneda et al.: "Convection induced by a cusp-shaped magnetic field for air in cube heated from above and cooled from below"Journal of Heat Transfer. 124. 17-25 (2002)
• [文献書誌] Toshio Tagawa et al.: "Convective and diffusive phenomena of air in a vertical cylinder under a strong magnetic field"Numerical Heat Transfer, Part B. (in press). (2002)
• [文献書誌] Masayuki Kaneda et al.: "Natural convection of liquid metal in a cube with Seebeck effect under a magnetic field"International Journal of Transport Phenomena. (in press). (2002)
• [文献書誌] Hiroyuki Ozoe: "Modelling of Transport Phenomena in Crystal Growth, Chapt. 7 Ed, by J.S.Szmyd and K. Suzuki Effect of a magnetic field in Czochralski silicon crystal growth"WIT Press., Southampton, U.K.. 362(201-237) (2000)