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The design of a biogas burner for Stirling engines depends on its ability to provide a sufficient heat which is not produced by conventional burners because of the limitation of the contact surface between flame-hot head and the low methane content in the biogas. Therefore, a special microscale combustion chamber for this kind of burner is necessary. In this work, we studied numerically the biogas combustion by a Swiss-roll burner in a small-scale combustor. The temperature distribution versus the biogas injection rate is investigated. A significant increase of the flame temperature is obtained with an improvement of the uniformity of the temperature distribution and the burner efficiency.

This work aims to investigate the impact of the cutting direction on the transfer properties of both the native cork and the treated by an optimized cycle at high temperature and boiling for the purpose to improve its mechanical characteristics in all three orthotropic directions. The study of the insulation performance is based on tracking the apparent mass diffusion coefficient (Dapp) variation in order to evolve a new material with the thermal, mass, acoustic and vibratory properties needed for various applications. TGA, IR and SEM analyzes are used to confirm the enhancement of the treated cork. The Dapp of the diffusing chemical species, NaCl (0.7M), is determined by conductimetric method. In transient mode, a mathematical model of mass transfer, which includes the diffusion parameters of the chemical species, is developed. Through the calibration of the model with the experimental measurements the Dapp values ​​were determined and then refined numerically by optimization using the Bat-Algorithm. The obtained results showed that the treatment improves the diffusion property of the native (DN) compared to the treaty (DA) with the values in the order of 10-12 and 10-13 m2.s-1 respectively with a relative uncertainty of 10-7. In addition, this investigation reveals that the radial diffusion coefficient (DR) is significantly higher than the tangential diffusion (DT) and longitudinal (DL) diffusion coefficients which both are almost of the same.