Flame Speed Calculator

Formula

To calculate the flame speed:

\[ S_f = \frac{\alpha \cdot R}{C_p \cdot \rho} \]

Where:

\( S_f \) is the flame speed (m/s)
\( \alpha \) is the thermal diffusivity (m²/s)
\( R \) is the reaction rate (1/s)
\( C_p \) is the specific heat capacity (J/kg·K)
\( \rho \) is the density (kg/m³)

Flame Speed Definition

Flame speed is the rate at which a flame front propagates through a combustible gas mixture. It is a critical parameter in combustion processes, influencing the efficiency and stability of combustion systems. Flame speed depends on various factors, including the type of fuel, the mixture ratio, temperature, pressure, and the presence of diluents or inhibitors. Understanding flame speed is essential for designing and optimizing combustion systems, such as engines, burners, and industrial furnaces, to ensure safe and efficient operation.

Example Calculation 1

Let's assume the following values:

Thermal Diffusivity (\( \alpha \)) = 0.01 m²/s
Reaction Rate (R) = 2 1/s
Specific Heat Capacity (\( C_p \)) = 1000 J/kg·K
Density (\( \rho \)) = 1.2 kg/m³

Using the formula:

\[ S_f = \frac{0.01 \cdot 2}{1000 \cdot 1.2} = 0.00001667 \]

The flame speed is 0.00001667 m/s.

Example Calculation 2

Let's assume the following values:

Thermal Diffusivity (\( \alpha \)) = 0.03 m²/s
Reaction Rate (R) = 5 1/s
Specific Heat Capacity (\( C_p \)) = 1500 J/kg·K
Density (\( \rho \)) = 0.8 kg/m³

Using the formula:

\[ S_f = \frac{0.03 \cdot 5}{1500 \cdot 0.8} = 0.00006250 \]

The flame speed is 0.00006250 m/s.