Modeling of coupled heat and mass transfer during drying of tropical woods Merlin Simo-Tagne a, * , Romain R  emond b , Yann Rogaume b , Andr  e Zoulalian c , Beguide Bonoma d a LERMaB, ENSTIB, 27 rue Philippe S eguin, PO Box 1041, F-88051 Epinal, France b University of Lorraine, LERMaB, ENSTIB, 27 rue Philippe S eguin, PO Box 1041, F-88051 Epinal, France c University of Lorraine, LERMaB, PO Box 239e54560, Vandoeuvre les Nancy, Nancy, France d University of Yaound e I, Higher Teacher Training College, Applied Physic Laboratory, PO Box 47, Yaound e, Cameroon article info Article history: Received 14 May 2015 Received in revised form 3 June 2016 Accepted 5 June 2016 Keywords: Drying Heat and mass transfer Modeling Simulation Experiment Tropical woods Central Africa abstract We have developed a model on drying of two tropical woods of ayous (Triplochiton Scleroxylon) and frake (Terminalia Superba) coming from Cameroon forests. Some thermophysical parameters used in the model were experimentally obtained in this work while the remaining properties were from literature. A comparison is doing between numerical results of our model, these given by the Luikov’s model and experimental data. Numerical simulation results from the developed model give close agreement with experimental results. We note that Luikov’s model not gives a satisfaction results in the non-hygroscopic domain in the case of frake. The present model can be used to explain the drying phenomenon of these two tropical species and can be applied to others species when necessary thermophysical parameters of these species are known. In a future work, it is important to integrate the influence of anatomical di- rection on our numerical and experimental results. © 2016 Elsevier Masson SAS. All rights reserved. 1. Introduction Tropical countries have vast forests that contain many species of wood [1e3]. These varieties enable the European and Asian to import enough woods to meet their needs. Unfortunately, the majority of these woods are exported in wood logs from Africa. However, many African countries such as Cameroon and Gabon require that the primary processing of these woods must be done locally [4]. This primary wood processing will create local job and promote employments. Moreover the transformed wood is a value added when it is sold abroad. However, due to the recent world- wide financial crisis, the economies of tropical countries do not depend mainly on the foreign markets. For high quality timber, it is very important to develop thermal drying technologies for tropical countries. This could be an issue for the immediate needs of wood preservation. Also, the utilization of the forest resource is optimized with ecological advantages such as carbon fixation and preservation of biodiversity. The first works on the drying have started since 1921 with W.K.Lewis’s works [5]. W.K.Lewis describes the drying as a conju- gation of the evaporation of humidity at the surface of porous material and the diffusion of the humidity from inside to outside of the product. Since 1929, many researches were dedicated on the drying with the objective to explain this physical phenomenon. The molecular diffusion is used by T.K.Sherwood to explain the internal migration of the water since 1929. Sherwood used the constant mass diffusion coefficients. In 1937, Ceaglske and Hougen have done many experiments on some materials and they demonstrate that the Sherwood’s hypothesis is not always true [6]. In 1935, E.A.Fisher presented three phases on the drying curve: (1) a con- stant rate drying period, (2) a linear falling rate drying period and (3) a nonlinear falling rate drying period. Each phase was repre- sented by an equation. In 1957, Philip and De Vries showed that the drying is a conjugation of heat and mass transfer. In 1962, Krisher is the first to use Fisher’s ideas to determine the sorption isotherms and equivalent conductivity of many products. Today, it is known that the diffusion and the movement of the internal wood water are the consequence of many mechanisms * Corresponding author. Tel.: þ33 613483787. E-mail address: simotagne2002@yahoo.fr (M. Simo-Tagne). Contents lists available at ScienceDirect International Journal of Thermal Sciences journal homepage: www.elsevier.com/locate/ijts http://dx.doi.org/10.1016/j.ijthermalsci.2016.06.012 1290-0729/© 2016 Elsevier Masson SAS. All rights reserved. International Journal of Thermal Sciences 109 (2016) 299e308