Flow resistance (TL)#

The Flow resistance (TL) block simulates the pressure drop in the thermal hydraulic network section based on the specified nominal operating conditions.

Law of conservation of mass(1):

(1)#\[\dot m_A+\dot m_B=0\]

where:

\(\dot m_A\) – mass flow at the inlet, [kg/s];

\(\dot m_B\) – mass flow at the outlet, [kg/s].

__ Energy conservation law__(2):

(2)#\[\phi_A+\phi_B=0\]

where:

\(\phi_A\) – energy flow at the input, [W];

\(\phi_B\) – energy flow at the output, [W].

Differential pressure

The differential pressure is determined according to the following formula (3):

(3)#\[\Delta p=K \cdot \dot m \cdot \sqrt {\dot m^2 + \dot m_{кр}^2}\]

where:

K – proportionality factor, [\(\frac{Pa \cdot s^2}{kg^2}\)];

\(\dot m\) – mass flow rate, [kg/s];

\(\dot m_{frc}\) – mass flow rate of transition to laminar flow mode, [kg/s].

The proportionality factor is calculated from the nominal values specified by user (4):

(4)#\[K=\frac{\Delta p_{ном}}{\dot m^2_{ном}}\]

where:

\(\Delta p_{nom}\) – nominal differential pressure, [Pa];

\(\dot m_{nom}\) – nominal mass flow rate, [kg/s].

1. Properties#

Property	Default Value	Description	Units of measurement
Nominal pressure drop	0.002	-	MPa
Nominal mass flow rate	0.2	-	kg/s
Ports cross-sectional area	0.01	-	m\(^2\)
Fraction of nominal mass flow rate for laminar flow mode	0.001	-	-

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Input	Input	-	-	Thermohydraulics
Output	Output	-	-	Thermohydraulics

In order to see the connection capabilities of the block, you need to go to page Description of block ports