Investigation on effect of Carman Kozeny term during melting in the Latent Heat Storage Devices

Efficient thermal storage improves sustainability and reduces environmental impact significantly. The enthalpy porosity approach is an efficient way to track the phase change numerically. It has been a widely used method to simulate the phase change problems. The Carman Kozeny term is a crucial parameter in this enthalpy porosity approach. It is known for influencing the melting pattern. However, its effect is rarely quantified in the research literature. In this work an extensive effort is made to understand the influence of the Carman Kozeny term on melting. To determine that influence, the mushy zone parameter is varied from 10 3 to 10 10 kg/(m 3 .s). The present work analyses the effects of the Porosity term (B term), the Carman–Kozeny term (A term), overall melting time, melt fraction evolution, Phase Change Material (PCM) average temperature, natural convection climb, and PCM temperature variation to comprehensively understand the thermal behaviour of the LHS system. The Carman Kozeny (A) term (A = M.B) exhibited an exponential decay with melt fraction (MF), with M-dependent effects strongest within the initial ∼20% of melting and becoming negligible at higher melt fractions. When plotted on a logarithmic scale, ln(A) remains linear up to MF ≈ 0.96, but displays pronounced ‘logarithmic non-linearity’ in the final 1% of melting.