TR 17

Technical report calculations and guidance.

TR 17 - Technical Report calculations and guidance.

This module contains equations and calculation methods from TR 17 technical report, focusing on fire dynamics principles and non-dimensional analysis for fire engineering applications.

Section 2

Section 2 - Non-dimensional parameters and scaling relationships.

This section contains equations and calculations for non-dimensional parameters used in fire dynamics analysis and scaling relationships for fire behavior correlation.

Equation 1 - Non-dimensional Heat Release Rate

ofire.tr_17.section_2.equation_1.calculate_nondime_hrr(q_dot, rho_a, c_p, t_a, g, h_e)

Calculate non-dimensional heat release rate (Equation 1).

This function calculates the non-dimensional heat release rate parameter used in fire dynamics calculations. This non-dimensional parameter is useful for scaling fire behavior and correlating experimental data.

\begin{align} \dot{Q}^* = \frac{\dot{Q}}{\rho_{\infty} c_p T_{\infty} \sqrt{g} H_e^{5/2}} \end{align}

where:

  • \(\dot{Q}^*\) is the non-dimensional heat release rate (dimensionless)

  • \(\dot{Q}\) is the heat release rate (kW)

  • \(\rho_{\infty}\) is the ambient air density (kg/m³)

  • \(c_p\) is the specific heat capacity of air (kJ/kg·K)

  • \(T_{\infty}\) is the ambient temperature (K)

  • \(g\) is the gravitational acceleration (m/s²)

  • \(H_e\) is the characteristic height (m)

Parameters:

  • q_dot (float) – Heat release rate (kW)

  • rho_a (float) – Ambient air density (kg/m³)

  • c_p (float) – Specific heat capacity of air (kJ/kg·K)

  • t_a (float) – Ambient temperature (K)

  • g (float) – Gravitational acceleration (m/s²)

  • h_e (float) – Characteristic height (m)

Returns:

Non-dimensional heat release rate (dimensionless)

Return type:

float

Assumptions:

To be completed

Limitations:

To be completed

Example

>>> import ofire
>>> # Calculate non-dimensional heat release rate for a 1000 kW fire
>>> q_star = ofire.tr_17.section_2.equation_1.calculate_nondime_hrr(
...     q_dot=1000.0,    # kW
...     rho_a=1.2,       # kg/m³
...     c_p=1.0,         # kJ/kg·K
...     t_a=293.0,       # K
...     g=9.8,           # m/s²
...     h_e=3.0          # m
... )
>>> print(f"Q* = {q_star:.4f}")