Abstract
It is necessary to measure horizontal and vertical velocity components for the research of boundary layer in the transition region. However, bondary layer thickness is very thin in this region. It is difficult to measure simultaneously these two velocity components. Therefore we manufacture a new hot-wire anemometer with two close wires. The main feature of this probe is extremely small compared with hot-wire probe existed, such as X- and V-configuration probe, in vertical size, and can be easily treated like I-configuration probe. We explore the near wake flow filed of hemispherical roughness using this probe. As a result, we find that this probe is very useful for the boundary layer flow measurements and velocity profiles data obtained are satisfied qualitatively.
