Introduction
When you obtain the simulation results from solarcfd.com, you will encounter one of two possible flow patterns in the attached video animations.
- Steady flow (sometimes also called stationary flow)
- Unsteady flow (sometimes also called instationary flow)
(You can reproduce below videos with the ground mounted simulation wizard.)
Steady flow
Some szenarios, usually when the flow hits a tilted panel from the front, a steady flow is achieved after some running-in period. In this case, there is some movement visible in the beginning, but after some time the flow does not change anymore over time. In the video it seems as if nothing happens. Indeed, air is flowing, but the flow pattern does not change.
Steady-state flow refers to the condition where the fluid properties like velocity and pressure at a point in the system do not change over time.
(slow motion video)
Unsteady flow
Some other szenarios, lead to an unsteady flow pattern. That means, that there are vortexes shedded in an undulating manner. The flow will never get steady. Thats leading to the fancy videos where vortexes are moving all the time.
Unsteady flow refers to the condition where the fluid properties like velocity and pressure at a point in the system do change over time.
(slow motion video)
