Description

The head loss coefficient in pipe stretches is a key parameter in the design of hydraulic systems, determining the pressure loss due to internal friction in pipes. This coefficient can be calculated using different approaches, depending on the available information:

• Velocity unknown: Determines the coefficient without prior knowledge of the fluid velocity.
• Velocity known: Calculates the coefficient considering a predefined flow velocity.
• Friction factor known: Evaluates head loss when the friction factor is already known.

The calculated value for the head loss coefficient $k_Q$ is such that $h_f=k_Q \cdot Q^2$.

Calculation Methods

Velocity unknown

Inputs:

Parameter	Standard Units	Description
Temperature	°C	Fluid temperature
Diameter	mm	Internal pipe diameter
Length	m	Length of the analyzed section
Roughness	mm	Internal roughness of the pipe

Outputs:

Parameter	Standard Units	Description
kQ	-	Head loss coefficient
Estimated friction factor	-	Calculated using the Churchill correlation

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Velocity known

Inputs:

Parameter	Standard Units	Description
Temperature	°C	Fluid temperature
Velocity	m/s	Flow velocity
Diameter	mm	Internal pipe diameter
Length	m	Length of the analyzed section
Roughness	mm	Internal roughness of the pipe

Outputs:

Parameter	Standard Units	Description
kQ	-	Head loss coefficient
Estimated friction factor	-	Calculated using the Churchill correlation

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Friction factor known

Inputs:

Parameter	Standard Units	Description
Friction factor	-	Predefined friction factor value
Diameter	mm	Internal pipe diameter
Length	m	Length of the analyzed section

Outputs:

Parameter	Standard Units	Description
kQ	-	Head loss coefficient

This calculation is widely used in engineering to optimize fluid transport systems, reducing energy losses and improving hydraulic efficiency.