Marangoni instability of self-rewetting films modulated by chemical reactions flowing down a vertical fibre

•A thin-film model is developed to study the modulation of chemical reactions.•Linear stability analysis shows that chemical reactions play diverse roles.•The interfacial temperature determines the direction of Marangoni flows.•Traveling wave solutions and transient simulations are performed for validation. This paper examines the Marangoni instability of a self-rewetting film coating on a vertical heated fibre and its modulation by chemical reactions. A single evolution equation based on the classic thin-film model is derived to study the flow dynamics. Linear stability analysis shows that without chemical reactions, wall heating plays a stabilizing role when Ti>T0 (Ti is the interfacial temperature and T0 is the temperature corresponding to the minimum of surface tension in self-rewetting fluids), and it plays a destabilizing role when TiT0 or Ti