Experimental investigation of a cooled thick fin in dry and humid air flows

The results of a study are reported in which a cooled, thick vertical fin was tested in a closed loop tunnel with and without condensation from the air flowing over it. In particular, the temperature distributions for the dry and wet fin cases, together with the condensate film thickness in the wet fin case, were investigated. From a flow visualization investigation, it was found that the boundary layer separates at the leading edge, resulting in a higher air heat transfer coefficient. The wet fin test results also indicated that the mode of condensation was dependent on fin surface characteristics and that the wet fin performance was governed by the air flow parameter. Within the laminar air flow range, the condensate film flowed downward under the action of gravity. However, at higher air velocities, both gravity and shear forces affected the condensate flow, a variation in the condensate film in the direction of air flow being noticed.     

The Use of Remote Sensing to Map the Areal Distribution of Cladophora Glomerata at a Site in Lake Huron

The areal distribution of the benthic alga Cladophora glomerata and the percent areal coverage of Cladophora within 45.8 m (150 ft) by 15.3 m (50 ft) model cells for a 2.8 km length of Lake Huron shoreline at Harbor Beach, Michigan, are determined by remote sensing techniques. Data were acquired on 21 July 1979, a calm, clear day over Lake Huron at an altitude of 305 m with an eleven-channel modular multispectral scanner mounted in a NASA C-131 aircraft. Cladophora is determined by a conventional maximum likelihood statistical supervised classification technique employing three of the scanner bands. An intensive field survey of the study site indicated that the computer classified imagery is representative of the Cladophora distribution at Harbor Beach. Classification accuracy is not determined because the site was not mapped by ground surveys. The percent of areal coverage of model cells by Cladophora ranges from 0% to 93%. Calculations based on these percentages indicate that the alga occupies an area of 38,704 m² at the study site. Overlapping flight lines resulted in duplicate measurements of many model cells. The reproducibility of results for these areas is good (R = 0.86 and standard error of estimate of 9.9%) when suitable well-defined Cladophora training sites are common to adjacent data sets. The reproducibility decreases in the absence of this condition.     

Finite difference analysis for laminar flow heat transfer in concentric annuli with simultaneously developing hydrodynamic and thermal boundary layers

The results of a finite difference analysis are presented for the problem of incompressible laminar flow heat transfer in concentric annuli with simultaneously developing hydrodynamic and thermal boundary layers, the boundary conditions of one wall being isothermal and the other wall adiabatic. This corresponds to the fundamental solution of the third kind according to the four fundamental solutions classified by Reynolds, Lundberg and McCuen¹. Firstly, the hydrodynamic entry length problem, based on the boundary layer simplifications of the Navier–Stokes equations, was solved by means of an extension of the linearized finite difference scheme used previously by Bodia and Osterle² to solve a similar problem between parallel plates. The energy equation is then solved, using the velocity profiles previously obtained, by means of an implicit finite difference technique. The accuracy of the numerical solution was checked by comparing results for the annulus of radius ratio 0.25 with the avaiable solution of Shumway and McEligot³.     

Advances in Taylor Vortex Flow: A report on the Fourth Taylor Vortex Flow Working Party meeting

A meeting of the Taylor Vortex Flow Working Party was held at the University of Karlsruhe from 20–26th May, 1985. It was attended by fifty-three engineers, mathematicians, physicists and chemists from Australia, Belgium, France, United Kingdom, U.S.A. and West Germany. During the colloquium, twenty-three papers were presented and discussed. The contributions covered the whole range of the subject including end-and initial-effects, new geometries, new working fluids and also wavy mode and time-dependent Taylor vortex flows. This report gives brief summaries of the papers presented.