Gelegentlicb einer Untersochung des Carbazols 5 4 9 1i:ibt.n wir daa 3-Amidocarbazol in grosseren Mengen geworincn uiid wurden durch die hervorragende Licbtempfiiidlichkeit von dessrll Diazorerbindung darauf gefiihrt, zu versuchen, es zur Erzengung photographischer Copien zu verwerthen. Das Diazocarbazol ist ans 3-Arnidncarbazol in der iiblicberr Weise leicbt zu erbalten und ziernlich besttindig. Es liefert, niit Phenolen und Aminen gekuppelt, substantive, Zuni Tbeil sehr lichtechte Farbstoffe, die sich ihrer gedrlckten, meist braunen oder rioletten Suancen halber zwar wenig zu praktischer Verwerthung in der Farbstofftecbnik eignen, die aber, besonders bei Verwendung von Napbtolen. Copien photograpbivcher Bilder mit sehr hiibechen Toner1 gebeir. Setzt man namlich Papier, welches mit eiuer Liisung yon Diazocitrbazol oberflachlich getrtinkt \i urde, unter eineni Diapositiv der Wirkung 'des Licbtes aus, so wild das Diazocarbazol an den lichtdiirchlassigen Stellen so zersetzt, dass es nicht mehr im Stande i d t ,
The present paper addresses the evolution of turbulence characteristics in wind turbine wakes immersed in a turbulent boundary layer. The study thereby focuses on finding physically consistent scaling laws for the wake width, the velocity deficit, and the Reynolds stresses in the far wake region. For this purpose, the concept of an added wake is derived which allows to analyse the self-similarity of the added flow quantities and the applicability of the non-equilibrium dissipation theory. The investigation is based on wind tunnel measurements in the wake of a three-bladed horizontal axis wind turbine model (HAWT) immersed in two neutrally-stratified turbulent boundary layers of different aerodynamic roughness length. The dataset also includes wake measurements for various yaw angles. A high degree of self-similarity is found in the lateral profiles of the velocity deficit and of the added Reynolds stress components. It is shown that these can be described by combined Gaussian shape functions. In the vertical, self-similarity can just be shown in the upper part of the wake. Moreover, it is observed that the degree of self-similarity is affected by the ground roughness. Results suggest an approximately constant anisotropy of the added turbulent stresses in the far wake, and the axial scaling of the added Reynolds stress components is found to be in accordance with non-equilibrium dissipation theory. It predicts a x − 1 decay of the added turbulent intensity I + , and a x − 2 evolution of the added Reynolds shear stresses Δ u i ′ u j ′ ¯ and the velocity deficit Δ u . Based on these findingsa semi-empirical model is proposed for predicting the Reynolds stresses in the far wake region which can easily be coupled with existing analytical wake models. The proposed model is found to be in good agreement with the measurement results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.