The current issue and full text archive of this journal is available at www.emeraldinsight.com/l 573-6105.htm Propagation of waves at an imperfect boundary between heat conducting micropolar thermoelastic solid and Rajneesh Kumar Department of Mathematics, Kurukshetra University, Kurukshetra, India Mandeep Kaur Department of Applied Sciences, Guru Nanak Dev Engineering College, Ludhiana, India, and S.C. Rajvanshi Department of Applied Sciences, Gurukul Vidyapeeth Institute of Engineering and Technology, Banur, India Received 8 June 2011 Revised 8 September 2011 Accepted 10 September 2011 Abstract Purpose - The purpose of this paper is to establish a mathematical model to investigate the propagation of waves at an imperfect boundary between heat conducting micropolar elastic solid and fluid media. Design/methodology/approach - Wave propagation and reflection methods have been applied to solve the problem. The expressions for refiection and transmission coefflcients are obtained. The corresponding derivation for the normal force stiffness, transverse force stiffness, transverse couple stiffness and perfect bonding has also been included. Findings - A computer program is developed and numerical results are computed to obtain the reflection and transmission coefficients of various reflected waves with incident waves. Some special and particular cases are also discussed. Originality/value - In this paper, stiffness effect on these amplitude ratios with the angle of incidence has been observed and depicted graphically. Keywords Micropolar solid, Miaopolarfluid.Wave propagation. Transmission coefficient, Normal force stiffness. Transverse force stiffness, Amphtude ratios. Solids, Fluids Paper type Research paper 1. Introduction Eringen (1966b) introduced the micropolar fiuids in which the local fluid elements were allowed to undergo only rigid rotations without sfretch. Micropolar fluids can support couple sfress, the body couples, asymmetric stress tensor. These possess a rotational field, which is independent of the velocity of fluid. A large class of fluids such as anisotropic fluids, liquid crystals with rigid molecules, magnetic fluids, cloud with ^"^'^^"^I'm^a dust, muddy fluids, biologicalfropic fluids, dirty fluids (dusty air, snow) over airfoil can ® Emerald Group Pubiishmg_umited be modeled more realistically as micropolar fluids. Various authors notably DOI 10.1108/15736101211235985 e Modeimg in