I have a model of a pipe that measures 15km in length. For SolidWorks restrictions the model is done to scale (1/100) and of this I have to develop an analysis with FlowSimulation to determine pressure drops, velocities, etc. Someone can help me to know where I can get equivalent formulas that allow me to define the boundary conditions for this model to scale. Thanks.

If you scale the length then you must adjust other properties. If you have not learned the theory of this then don't attempt the job.

There is a reason why people spend years studying engineering at university.