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.Variations in density, specific heat capacity, insulation thickness, and excitation pulsation significantly affect the magnitude and frequency dependence of the thermal impedance, whereas the influence of the metal-flax Simulation study …