Ethylene Ethene Acetene C2H4 Thermal Conductivity Temperature Pressure

Reference data and engineering information about ethylene ethene acetene c2h4 thermal conductivity temperature pressure for fluid mechanics applications.

Overview

Engineering reference data for Ethylene Ethene Acetene C2H4 Thermal Conductivity Temperature Pressure in fluid mechanics.

Key Formulas

Reynolds Number

$Re = \frac{\rho v D}{\mu}$

Ratio of inertial to viscous forces — determines flow regime.

Bernoulli's Equation

$P + \frac{1}{2}\rho v^2 + \rho g h = \text{const}$

Conservation of energy for steady, inviscid, incompressible flow.

Continuity Equation

$A_1 v_1 = A_2 v_2$

Conservation of mass for incompressible flow.

Darcy-Weisbach

$\Delta P = f \frac{L}{D} \frac{\rho v^2}{2}$

Pressure drop due to friction in a pipe.

Variables

Symbol	Description	Unit
$Re$	Reynolds number	—
$\rho$	Fluid density	kg/m³
$v$	Flow velocity	m/s
$D$	Characteristic dimension	m
$\mu$	Dynamic viscosity	Pa·s
$P$	Pressure	Pa
$f$	Darcy friction factor	—

Phase Behavior and Thermal Conductivity Data

The thermal conductivity of ethylene exhibits significant variation across its different phases (solid, liquid, gas, supercritical) and is strongly influenced by both temperature and pressure. The relationship is non-linear, particularly near the critical point and during phase transitions.

Key Observations from Data:

Liquid Phase: Thermal conductivity decreases significantly as temperature increases, from ~270.7 mW/(m·K) at 104 K to ~81.6 mW/(m·K) near the critical temperature.
Gas Phase (at low pressure): Thermal conductivity is much lower and increases with temperature (e.g., from ~6.8 mW/(m·K) at 104 K to ~20.6 mW/(m·K) at 300 K).
Pressure Effect: At a given temperature, increasing pressure generally increases thermal conductivity, especially for gas-phase ethylene and near the critical region.
Critical Region: There is a sharp increase in thermal conductivity for gas at equilibrium pressure as temperature approaches the critical point (282.4 K), rising from ~21.2 mW/(m·K) at 255 K to ~39.2 mW/(m·K) at 275 K.

Core Definition Formula

The fundamental definition of thermal conductivity ( $\lambda$ ) can be expressed as:

$\lambda = \frac{\dot{Q} \cdot L}{A \cdot \Delta T}$

Where:

$\dot{Q}$ is the heat transfer rate (W),
$L$ is the material thickness (m),
$A$ is the cross-sectional area (m²),
$\Delta T$ is the temperature difference across the material (K).

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