Simulation study of the thermal behaviour of flax material under Dynamic-Frequency conditions based on thermal impedance: Application to a Hollow Cylindrical Calorimetric Vessel

This study investigates the dynamic thermal behaviour of flax as a potential insulating material under frequency-dependent thermal excitation.A cylindrical aluminium vessel, analogous to a calorimetric system, is insulated with a layer of flax and filled with hot water initially maintained at 90 °C, while the surrounding ambient temperature is fixed at 27 °C.A thermal contact resistance is considered at the aluminium-flax interface to account for interfacial heat-transfer effects.Heat transfer through the insulation is analysed in both radial and axial directions.Using an electrical-thermal analogy, the thermal impedance of the system is formulated and evaluated as a function of key thermophysical and geometric parameters, including flax density, specific heat capacity, insulation thickness, excitation pulsation, and metal-flax contact resistance.The results demonstrate that the dynamic thermal response of flax is governed primarily by its intrinsic thermophysical properties and the characteristics of the imposed thermal excitation.