On the Instability of a Flow Past a Spherical Cap Body

We have performed an experimental flow visualization for a flow over an axisymmetric body which has a spherical shape. To explain the flow visualization images, we have also carried out the global stability analysis. The aspect ratio (χ) of the spherical shape body is defined as χ = 2W/D, where W and D are the width and the base diameter, respectively. We present here some flow visualization and stability calculations for χ = 0.6. We used Laser-Induced Florescence (LIF) technique for flow visualization. The flow speed has been set such that the Strouhal number is found to be 0.12, which is similar to the vortex shedding frequency of a sphere. The wake structure is compared with the global Eigen modes obtained from the stability analysis.