Determination of the critical reynolds number for flow over symmetric NACA airfoils

Due to copyright restrictions, the access to the full text of this article is only available via subscription.The determination of the critical Reynolds number is of practical importance in many engineering applications, particularly in determining the aerodynamic characteristics of air vehicles. In this study, we numerically investigated the laminar-turbulent transition location over NACA 0012, 0015, and 0018 airfoil profiles in order to determine their lower critical Reynolds number. To this end, a CFD FORTRAN code was developed based on the hybrid viscous-inviscid interaction method with an incorporated eN transition method to model the boundary layer flow around airfoil profiles. The results, in general, indicated that the laminar-turbulent transition location over an airfoil is strongly dependent on the Reynolds number and moves toward the downstream as the Reynolds number decreases. The lower critical Reynolds number was then defined as the velocity at which the flow becomes laminar over the airfoil, which corresponds to the conditions that the transition point located at the trailing edge of the airfoil. The lower critical Reynolds number for flow over NACA 0012, 0015, and 0018 airfoils were, therefore, determined to be 1 × 105, 5 × 104, and 3.5 × 104, respectively. Moreover, the variations of the transition location with the angle of the attack showed that the transition point moves toward the leading edge of the airfoil as the angle of attack increases

ZORO: Prospective randomized multicenter-study to prevent chemotherapy induced ovarian failure with the GnRH-Agonist Goserelin in young hormone insensitive breast cancer patients receiving anthracycline containing (neo-) adjuvant chemotherapy (GBG 37)

Chemical sciences in Brazil are growing fast and being one of the main supports for the continuous development of the country. Inspired on the 15th Brazilian Meeting on Analytical Chemistry, ENQA, with a record number of participants and communications, we have decided to review recent developments in analytical chemistry in Brazil. We have chosen the same application areas used for the thematic organization of the ENQA and have searched papers published by Brazilian authors in 7 major and general journals in analytical chemistry. The two scientific journals published by the Brazilian Chemical Society were also searched. This review is not comprehensive, but the selected papers published after 2008 shown an impressive overview of the area. We may conclude that analytical chemistry is healthy and growing in Brazilian scenario and certainly will attend the demands of Brazil as an emerged power.A química brasileira está crescendo rapidamente, sendo um dos principais alicerces para o contínuo desenvolvimento do país. Inspirados no 15º Encontro Nacional de Química Analítica, ENQA, com um número recorde de participantes e comunicações, decidiu-se revisar os recentes desenvolvimentos em química analítica no Brasil. Foram escolhidas as mesmas áreas de aplicação adotadas para a organização temática do ENQA e selecionados artigos publicados por autores brasileiros em 7 periódicos de ampla penetração na área. Os dois periódicos científicos editados pela Sociedade Brasileira de Química também foram pesquisados. Esta revisão não é exaustiva, porém os trabalhos selecionados após 2008 mostram uma significativa visão geral da área. Pode-se concluir que a química analítica brasileira está saudável, em crescimento e certamente atenderá as demandas do país como uma potência emergida