Abstract The paper studies convection in a horizontal annular gap filled with a magnetic fluid or gaseous oxygen under the influence of gravitational and magnetic forces. A current-carrying conductor and an external uniform magnetic field magnetizing an internal cylinder of a material with high magnetic permeability were considered as a source of a magnetic field. The influence of the shape of the inner cylinder and the magnitude of the magnetic field gradient on the heat transfer was studied. It is found that the strength of the magnetic field created by a current-carrying conductor is insufficient to compete with gravitational convection. In the absence of gravity, a variety of convective structures and the hysteretic nature of the transition between them were discovered. The shape of the conductor is an additional factor affected the convection. The effect of a high gradient magnetic field of a magnetizing inner cylinder on convection is studied too. In the case of magnetic fluid, this can ensure the excess of magnetic forces over gravitational by hundreds of times. Heat transfer in an external field with strength of 150 kA/m from a circular magnetized cylinder can be increased 3–4 times, and in a field of 1000 kA/m 4–6 times compared with natural gravitational convection. Heat transfer can be further enhanced by 40–50% by choosing the shape of the inner cylinder. The magnetic field can increase heat transfer through an annular gap filled with gaseous oxygen, 2 times.

中文翻译：

---

内边界形状对水平圆柱体之间环隙中热磁对流的影响：传热增强

摘要 本文研究了在重力和磁力影响下充满磁性流体或气态氧的水平环形间隙中的对流。将载流导体和外部均匀磁场磁化具有高磁导率的材料的内部圆柱体作为磁场源。研究了内筒的形状和磁场梯度的大小对传热的影响。发现由载流导体产生的磁场强度不足以与重力对流竞争。在没有重力的情况下，发现了各种对流结构以及它们之间过渡的滞后性质。导体的形状是影响对流的另一个因素。还研究了磁化内筒的高梯度磁场对对流的影响。在磁性流体的情况下，这可以确保磁力超过重力数百倍。与自然重力对流相比，圆形磁化圆柱体在强度为 150 kA/m 的外场中的传热可提高 3-4 倍，在 1000 kA/m 的场中可提高 4-6 倍。通过选择内筒的形状，传热可以进一步提高 40-50%。磁场可以将通过充满气态氧的环形间隙的热传递增加 2 倍。与自然重力对流相比，圆形磁化圆柱体在强度为 150 kA/m 的外场中的传热可提高 3-4 倍，在 1000 kA/m 的场中可提高 4-6 倍。通过选择内筒的形状，传热可以进一步提高 40-50%。磁场可以将通过充满气态氧的环形间隙的热传递增加 2 倍。与自然重力对流相比，圆形磁化圆柱体在强度为 150 kA/m 的外场中的传热可提高 3-4 倍，在 1000 kA/m 的场中可提高 4-6 倍。通过选择内筒的形状，传热可以进一步提高 40-50%。磁场可以将通过充满气态氧的环形间隙的热传递增加 2 倍。