The Chao and Fagbenle’s modification of Merk series has been employed for the analysis of forced convection laminar thermal boundary layer transfer for non-isothermal surfaces. In addition to the Prandtl number (Pr) and the pressure gradient (∧), a third parameter (temperature parameter, γ ) was introduced in the analysis. Solutions of the resulting universal functions for the thermal boundary layer have been obtained for Pr of 0.70, 1.0 and 10.0 and for a range of ∧ . The results obtained for the similarity equations agreed with published results within very close limits for all the ∧’s investigated.
enhancement has been considered as an effective
way of improving coefficient of performance
(COP) of refrigeration systems and magnetic enhancement is one of these
methods. A model of magnetic field enhancement in ammonia-water absorption systems
is presented in this paper. A numerical model using finite difference scheme
was developed based on the conservation equations and mass transport
relationship. Macroscopic magnetic field force was introduced in the momentum
equation. The model was validated using data obtained from the literature. Changes in the physical properties of ammonia
solution while absorbing both in the direction of falling film and across its
thickness were investigated. The magnetic field was found to have some positive
effect on the ammonia-water falling film absorption. The results indicate that
absorption performance enhancement increased with magnetic intensity. The COP
of simple ammonia solution absorption refrigeration system increased by 1.9%
and 3.6% for magnetic induction of 1.4 and 3.0 Tesla respectively.