Final answer:
The specific minimum hose line size for lumberyard fires isn't provided, and one would need to consult firefighting guidelines for accurate data. For the calculation of Reynolds numbers, the formula involves the velocity of the fluid, the hydraulic diameter, and the kinematic viscosity. A Reynolds number above 4000 generally indicates turbulent flow, which is likely in this scenario.
Step-by-step explanation:
A student has asked about the minimum hose line size that should be used in lumberyard fires to wet down immediate exposures. However, a specific minimum size isn't provided in the resources above. Therefore, based on general firefighting knowledge, a larger diameter hose, perhaps 1½ inch or larger, is typically used for fighting exposures in lumberyard fires due to the capacity for high water flow. But to determine the actual size, consulting firefighting guidelines or a fire protection engineer would be necessary.
To address the question regarding how to calculate the Reynolds numbers for a fire hose and nozzle given certain parameters: The Reynolds number is a dimensionless quantity used in fluid mechanics to predict flow patterns in different fluid flow situations. To calculate it, you need the velocity of the fluid, the hydraulic diameter of the hose or nozzle, and the kinematic viscosity of the fluid.
The formula for calculating a Reynolds number (Re) is: Re = (velocity * hydraulic diameter) / kinematic viscosity. The calculated Reynolds number determines whether the flow is laminar or turbulent. Typically, a Reynolds number above 4000 indicates turbulent flow.