Does this calculate a turbulent friction factor from pipe material?

No. For non-laminar work, enter a Darcy friction factor from a controlled applicable source or calculation.

What happens in the transition range?

No friction factor is interpolated. Use a documented factor and project procedure; transition is disturbance-dependent.

Are fitting K values built in?

No. Enter a documented summed loss coefficient referenced to the same mean velocity, or leave it zero.

Is this total system pressure drop or pump head?

No. It reports only the entered straight-pipe friction and documented-K dissipative terms; elevation, acceleration, equipment and other effects are excluded.

Controlled loss coefficients — no transition interpolation

Source-Gated Darcy–Weisbach Loss Arithmetic

Calculate dissipative loss for one constant-ID straight length plus an optional documented summed K. Supply a controlled Darcy factor,or use the narrow verified fully developed laminar route.

Darcy f explicitlyNo roughness presetsNo K presets

Friction-factor basis

Actual volumetric flow Q

Flow unit

Actual constant internal diameter D

Diameter unit

Straight constant-ID length L

Length unit

Same-state density ρ

Density unit

Documented Darcy friction factor fD

Same-state kinematic viscosity ν

Viscosity unit

Documented summed loss coefficient ΣK (blank=0)

Section,state,f/K or laminar evidence source

All inputs describe the same steady single-phase Newtonian state and constant full circular ID.The result is dissipative straight-pipe plus entered-K loss between documented planes.Entered f is the Darcy—not Fanning—factor and is applicable to this Re,relative roughness and state;or the laminar route has controlled fully developed laminar evidence.Each K uses this same mean-velocity reference.Elevation,acceleration,equipment and other terms are separate.

Entered-model dissipative pressure loss

—

Straight-pipe friction term

—

Documented-K term

—

Mean velocity

—

Darcy factor / Reynolds basis

—

Partial-system dissipative loss only.

v̄=4Q/(πD²); Δpmajor=fD(L/D)(ρv̄²/2); ΔpK=ΣK(ρv̄²/2); Δploss=Δpmajor+ΔpK

fD is the Darcy friction factor,not the Fanning factor.ΣK is dimensionless and must be referenced to the same mean velocity.The equations return positive dissipative loss magnitude,not a signed static-pressure difference or a complete energy equation.

Laminar route

ReD=v̄D/ν; fD=64/ReD

The 64/ReD route is restricted to controlled fully developed laminar Newtonian flow in a full straight circular pipe and is rejected at or above the conventional ReD=2300 screen.Roughness does not enter that theoretical relation.

No transition model

No linear interpolation between laminar and turbulent friction factors is used.Transition is disturbance-dependent.For turbulent or transition work,supply fD from a documented method whose inputs,range and conventions match the assessed state.

Not calculated: material-based roughness,Colebrook/Moody selection,fitting K values,pipe sizing,acceptable loss,pump duty,elevation,acceleration,compressibility,two-phase flow,heat transfer,water hammer or cavitation.

แหล่งข้อมูล

Louisiana Tech Darcy–Weisbach and empirical K-factor scope; ERAU fully developed laminar 64/Re relation; Princeton disturbance-dependent transition; NIST conversion factors.