Transformer oil-based nanofluids velocity measurement under DC voltage

The transformer oil-based nanofluids have significant improvements in their thermal conductivity and dielectric strength than traditional transformer oil, so they have a wide prospect of application. In order to explore the mechanism of the thermal dissipation enhancement of transformer oil-based nanofluids, the flow field distribution of them under the DC voltage were measured by particle image velocimetry (PIV), and the results were compared with that of the traditional transformer oil. The test samples were placed in an organic glass and two circular planar electrodes for 1cm apart were placed in the center of the glass in order to produce a uniform electric field. The tracer particles were hollow glass spheres of 10 μm diameters. The flow field measurement profile was the center of the electrode plate and the test samples were applied DC 10kV, 15kV and 20kV, respectively. The results show that the flow field distribution of transformer oil-based nanofluids is more regular and the flow velocity is faster than those of the traditional transformer oil, and its flow velocity is gradually slowed down from the positive plate to the negative plate. It is concluded that the flow field property of the transformer oil-based nanofluids is changed due to the addition of nanoparticles, which explains why the heat dissipation effect of transformer oil-based nanofluids is enhanced. The assumption of the electric double layer structure is reasonable. The investigation provides a new idea for exploring the reasons for the enhancement of the thermal dissipation of transformer oil-based nanofluids.