Search results
Results from the WOW.Com Content Network
The following table gives flow rate Q such that friction loss per unit length Δp / L (SI kg / m 2 / s 2) is 0.082, 0.245, and 0.816, respectively, for a variety of nominal duct sizes. The three values chosen for friction loss correspond to, in US units inch water column per 100 feet, 0.01, .03, and 0.1.
In fire protection engineering, the K-factor formula is used to calculate the volumetric flow rate from a nozzle. Spray nozzles can for example be fire sprinklers or water mist nozzles, hose reel nozzles, water monitors and deluge fire system nozzles.
In engineering, the Moody chart or Moody diagram (also Stanton diagram) is a graph in non-dimensional form that relates the Darcy–Weisbach friction factor f D, Reynolds number Re, and surface roughness for fully developed flow in a circular pipe. It can be used to predict pressure drop or flow rate down such a pipe.
The flow rate can be converted to a mean flow velocity V by dividing by the wetted area of the flow (which equals the cross-sectional area of the pipe if the pipe is full of fluid). Pressure has dimensions of energy per unit volume, therefore the pressure drop between two points must be proportional to the dynamic pressure q.
The Hazen–Williams equation is an empirical relationship that relates the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction. It is used in the design of water pipe systems [1] such as fire sprinkler systems, [2] water supply networks, and irrigation systems.
These arise from both pressure and flow. The magnitude of the axial tension in a fire hose is = + /, where p is pressure in the hose relative to the ambient pressure, A 1 is the hose cross-sectional area, ρ is the water density, and Q is the volumetric flow rate. [19]
Churchill equation [24] (1977) is the only equation that can be evaluated for very slow flow (Reynolds number < 1), but the Cheng (2008), [25] and Bellos et al. (2018) [8] equations also return an approximately correct value for friction factor in the laminar flow region (Reynolds number < 2300). All of the others are for transitional and ...
The probable intensity and extent of a fire inside the building are indicated by factors including the building use, the building height, the items contained inside the building and their arrangement. These variables are compared to tables and values expressed in the model codes. The values in these tables are based on fire tests and loss history.