Stratification and internal waves around a underwater object

In normal simulations of fluid dynamics at the underwater area the density is regarded as constant in time and space. This is valid in the near field but when a realistic scenario is considered the density in the oceans vary. This is due to diferences in pressure, salinity and temperature where pressure is accounted for a very small part either of the other two tend to dominate the denity gradient. In this study the salinity is considered to be the dominant part and the incompressible equations are adjusted to accomplish the density gradient. It turns out that the far field wake are affected by this density gradient and that the wake turn out to be quasi two dimensionell and it is in this phase the so called pan-cake eddies occur. Another phenomena attributed to the density gradient are internal waves which in shape and form are similar to surface waves with the difference that, in linear stratification, they propagate in the vertical direction and thus evenually reaches the surface. This study shows that if interest is in the late wake the variations in density occuring in real scenarios are an essential part to include in the model. The variations in salinity due to the wake are likely to affect the magnetic and electrical field and these phenomena are to be focused in future studies.