Natural convection in a vertical slot: accurate solution of the linear stability equations

The linear stability of natural convection in a fluid between vertical hot and cold walls was studied using a collocation method. Seven figure accurate results for monotonic disturbances were obtained by Ruth (1979) using numerical power series, but this method is intrinsically limited and failed for Pr ? 10 . In contrast, Chebyshev collocation converges more rapidly and allows the computation of results at higher Pr for which oscillatory disturbances dominate. Accurate results are now obtained across the entire Prandtl number range. These match the zero and infinite Pr asymptotes which are also refined here