Analysis of MHD nanofluid forced convection and phase change process in a PCM mounted corrugated and partly elastic partitioned channel system with area expansion

In this study, effects of using wall corrugation and nano-enhanced magnetic field in a channel with area expansion and elastic interface on the phase change and thermal process are examined by using finite element method with ALE (Arbitrary Lagrangian-Eulerian). A range of values for the relevant parameters are included in the simulations: the flow Reynolds number (Re) between 100 and 1000; the elasticity of the flexible partition (E between 10 5 and 10 9 ); the Hartmann number (Ha) between 0 and 60; the amplitude of the wavy wall (A between 0.01 and 0.35); and the wave number of corrugation (N between 2 and 20). Complete phase transition ( t F ) with Re shows non-monotonic behavior while variations of t F up to 57 % and 50 % are obtained for the upper and lower PCM under wavy wall with varying Re. For upper PCM, the variation of t F with elastic modulus becomes 21 %-25 %. When E is changed, the average Nu increment with a corrugated wall is 11 %. When the magnetic field is applied with maximal strength, thermal performance is enhanced and the phase transition process is accelerated. For the upper and lower PCM zones, reduction of t F with Ha yields 44 % and 33 %, respectively. For the upper and lower PCM zones, the full transition time decreases with higher corrugation amplitudes by 14.7 % and 12.5 %, respectively. Average Nu increments of 10 % and 7.5 % are found by raising the corrugation amplitude and wave number to their maximum values. A significant reduction of t F , around 54 %, is obtained with the introduction of wavy walls with magnetic field and nanofluid when compared to the reference case (flat channel using base fluid and without magnetic field effects). Although the upper wall’s corrugation further enhances thermal performance, magnetic field has a bigger impact on thermal performance than wavy shape.