American Journal of Mechanical Engineering
http://www.sciepub.com/journal/AJME
American Journal of Mechanical Engineering is a peer-reviewed, open access journal that publishes original research articles and review articles in all areas of Mechanical Engineering. The aim of the journal is to provide academicians, researchers and professionals a platform to share cutting-edge development in the field of Mechanical Engineering.Science and Education Publishingen2013 Science and Education Publishing Co. Ltd All rights reserved.American Journal of Mechanical Engineering
8
3
January 2020
2013 Science and Education Publishing Co. Ltd All rights reserved.
Numerical Investigation of an Offshore Oscillating Water Column
http://pubs.sciepub.com/ajme/8/3/1
TM Fluent to simulate six different offshore OWC configurations. The waterside chamber angle, θ_{1}, shoreside chamber angle, θ_{2}, and immersion extension depth d, were varied to evaluate their effect on pneumatic power and efficiency. It was determined that configuration parameters with θ_{1 }= 45^{o}, θ_{2 }= 90^{o }and d = 0 m produced the highest power with an efficiency of 23.1%; results showed that this case had a higher static pressure inside the duct which was the predominant reason for a higher pneumatic power. The cases with an additional extension into the water, d, was found to reduce the pneumatic power when compared to a similar case without anextension.]]>
Frimpong Opoku, Michael Atkinson, Mohammad Nasim Uddin
2020-09-16Science and Education Publishing2020-09-16388810510.12691/ajme-8-3-1
Why Heat Transfer Coefficients Are Unnecessary and Undesirable, and How Heat Transfer Problems Are Solved without Them
http://pubs.sciepub.com/ajme/8/3/2
q has been calculated by multiplying heat transfer coefficient h times boundary layer temperature difference ΔT. Since h times ΔT equals q, h must be a symbol for (q/ΔT) because (q/ΔT) timesΔT equals q.h (ie q/ΔT) is generally calculated from correlations derived from experiments in which q data and ΔT data are used to obtain (q/ΔT){ΔT} correlations-ie h{ΔT} correlations. (It is not possible to obtain h data because h is not a parameter. h is the ratio of two parameters). Heat transfer coefficients are unnecessary and undesirable. It is self-evident that any problem that can be solved using q, q/ΔT (ie h), and ΔT can also be solved using only q and ΔT. Therefore h (ie q/ΔT) is unnecessary.h (ie q/ΔT) is undesirable because, when q is a nonlinear function of ΔT (as in free convection, condensation, and boiling), h (ie q/ΔT) is an extraneous variable, and it greatly complicates problem solutions. When h has been abandoned, convective heat flux is determined from q{ΔT} correlations that result from q data and ΔT data, or from the transformation of h{ΔT} correlations. (Transformation from h{ΔT} correlations to q{ΔT} correlations requires that h be replaced by q/ΔT, and that q and ΔT be separated.). The text includes example problems that validate the conclusion that h (ie q/ΔT) is unnecessary and undesirable, and demonstrate that the solution of nonlinear problems is much simpler if h is abandoned.]]>
Eugene F. Adiutori
2020-09-17Science and Education Publishing2020-09-173810611010.12691/ajme-8-3-2