Experimental study on the second-order buoyancy of magnetic fluid

The buoyancy principle of magnetic fluid is one of the most attractive effect of magnetic fluid statics. The buoyant force suffered by the permanent magnet immersed in magnetic fluid is greater than Archimedes force, and the difference is called the second-order buoyancy of the magnetic fluid. But it is too difficult to directly calculate the buoyancy due to the complexity of magnetic field. Moreover numerical calculation employs too many assumptions. So in this paper the experimental method is adopted firstly to show the suspension of permanent magnet immersed in magnetic, and then to measure the second-order buoyancy received by permanent magnet immersed in magnetic fluid, which depends on the distance between the magnet and the wall of vessel. The influence of the diameter of cylindrical vessels, the size of magnets and the saturation magnetization of magnetic fluids on the buoyancy is also analyzed qualitatively.