Motion of an Elliptic Vortex in a Uniform Shear Flow

Motion of an elliptic vortex of uniform vorticity in a uniform straining and vorticity flow is solved exactly. The elliptic shape is preserved and the area of the vortex is conserved but the axis ratio of the ellipse changes in general. Depending on the magnitudes of the vorticity in the vortex and the strain and the vorticity of the shear flow, this vortex exhibits various types of motion such as rotation and nutation around its centre. When the strain is very strong, the vortex is always elongated infinitely in the direction of the strain. A stationary elliptic vortex can exist in a weaker straining flow.