Thermal diffusivity measurements using insulating and isothermal boundary conditions.

Area of Science:

• Materials Science
• Thermodynamics
• Experimental Physics

Background:

• Traditional methods for measuring thermal diffusivity, such as steady-state and laser flash techniques, present limitations.
• Steady-state methods often suffer from significant experimental errors and inaccuracies.
• Transient techniques like laser flash analysis are costly and demand specialized equipment and complex data analysis.

Purpose of the Study:

• To introduce a novel, low-cost experimental setup for evaluating thermal diffusivity.
• To demonstrate an accurate and accessible alternative to existing thermal diffusivity measurement techniques.
• To validate the method's performance across a range of materials.

Main Methods:

• Imposing hot isothermal and insulating boundary conditions on a flat disk sample.
• Analyzing the transient temperature profile on the insulated side of the sample.
• Relating thermal diffusivity to the inverse of a characteristic time constant derived from the temperature profile.

Main Results:

• The thermal diffusivity was found to be inversely proportional to the measured time constant.
• Measurements were successfully conducted on materials with thermal diffusivity ranging from 0.1 to 3 mm²/s.
• The experimental setup achieved an accuracy of 5% or better compared to established literature values.

Conclusions:

• The developed experimental setup provides an accurate and cost-effective method for determining thermal diffusivity.
• This novel approach integrates modeling of interface effects and requires only small sample sizes.
• The method presents a viable alternative for characterizing thermal transport properties, particularly for materials with low to medium thermal diffusivity.