Final answer:
If the pressure inside the hanger is equal to the freestream pressure, the flow would theoretically remain attached to the surface. This is based on the continuity equation and the assumption of no adverse pressure gradients causing flow separation. However, more context on the flow conditions and surface geometry is needed for a definitive answer. so, option b is the correct answer.
Step-by-step explanation:
If the pressure inside the hanger is equal to the freestream (ambient atmospheric) pressure, the flow would theoretically remain attached to the surface. In fluid dynamics, the continuity equation states that the product of the density, velocity, and cross-sectional area of a fluid remains constant along a streamline. When considering the behavior of real fluids, however, the situation could be affected by other factors such as boundary layer development and viscosity which can lead to flow separation if adverse pressure gradients are encountered.
In the context provided, if the pressure inside and outside is the same, it implies that there is no adverse pressure gradient to cause flow separation, hence option (b) the flow will remain attached to the surface is the most likely answer. Nonetheless, without more context or specific information about the shape of the hanger and the flow conditions, this remains a theoretical response.
Flow separation generally occurs when the boundary layer flow decelerates and reverses direction, which can happen with adverse pressure gradients or significant changes in the geometry of the surface upon which the fluid is flowing.