Donald S. Scott

Bio: Donald S. Scott is an academic researcher from University of British Columbia. The author has contributed to research in topics: Plug flow & Stratified flow. The author has an hindex of 1, co-authored 1 publications receiving 43 citations.

Properties of Cocurrent Gas-Liquid Flow

Abstract: Publisher Summary Two-phase gas–liquid glow is encountered in an increasing number of important situations, and a clear understanding of the rates of transfer of momentum, heat, and material are required for logical and careful design and operation of a very wide variety of chemical engineering equipment and processes. In the production and transport of crude petroleum and petroleum products, two-phase flow is finding increasing use. Two-phase flow systems may be classified initially by composition, as containing a single component, or two or more components with any one component present in both phases or only essentially in one or the other phase. Varieties of flow patterns include bubble flow, plug flow, stratified flow, wavy flow, snug flow, annular flow, mist or spray flow. The problem of two-phase-flow classification is complicated by the inevitable differences because of individual interpretations of visual observations and also by differences in terminology. This chapter investigates a number of definite flow patterns. In the case of single-component two-phase flow—such as in vaporizing water—physical equilibrium is commonly assumed and seems to yield reasonable results, even though it might seem that supersaturation could occur. The rate of mass transfer among phases, therefore, is not a limiting process for single component flow.

The Flow of Liquids in Thin Films

Abstract: Publisher Summary This chapter studies fluid–flow characteristics of liquids in layers, with and without a superimposed gas velocity. The types of turbulence in layers need to be investigated and also the nature of a laminar layer containing ripples. As regards the theoretical studies of film flow, it is shown in the chapter that it is possible to predict quite accurately the flow behavior in the smooth laminar flow regime of the film; unfortunately, this flow regime is not of great practical importance. The Kapitsa theory for wavy film flow appears to apply over only a very limited part of the total wavy flow regime. Several new experimental techniques for the study of film flow have been developed. Film flow is a special case of two-phase flow. It takes place along a solid surface of some sort, with only one free surface. The second phase in contact with the free surface of the film may be either a gas or a second liquid, which may be at rest or in motion relative to the solid surface on which the film flows. Film flow is distinguished from other forms of two-phase flow by the presence of large interfaces of basically simple geometrical configuration. Two-phase flows are also often further classified as single-component. The occurrence and applications of film flow in modern technology are numerous and important.

Condensation heat transfer and flow pattern inside a herringbone-type micro-fin tube

Abstract: Condensation heat transfer and pressure drop of R410A and R22 in a newly proposed herringbone-type micro-fin tube are measured and compared to those of a helical micro-fin tube and a smooth tube. The heat transfer coefficient of the herringbone micro-fin tube is higher than that of the helical micro-fin tube in the high mass velocity region, while it has slightly lower value in the low mass velocity region. Pressure drop of the herringbone micro-fin tube is, however, higher than that of the helical micro-fin tube. Flow patterns of the herringbone micro-fin tube are observed and the heat transfer enhancement mechanism is discussed. The heat transfer coefficient and pressure drop of the helical micro-fin tube is predicted well with previously proposed correlations, while those of the herringbone-type micro-fin tube has higher value than the predicted values. Preliminary correlations for the pressure drop and the heat transfer coefficient are proposed for the herringbone micro-fin tube.

Experimental study on condensation heat transfer and pressure drop in horizontal smooth tube for R1234ze(E), R32 and R410A

Abstract: Experimental condensation heat transfer and pressure drop of R1234ze(E), trans-1, 3, 3, 3-tetrafluoropropene (trans-CHF CHCF 3 ) in a horizontal smooth tube are measured and compared with R32 and the nearly azeotropic HFC refrigerant blend R410A. The effects of mass flux and saturation temperature on heat transfer and pressure drop have been conducted and analyzed. The copper tube with inner diameter of 4.35 mm and length of 3.6 m was used as the test sections. The tests were conducted for mass fluxes varying from 150 to 400 kg (m −2 s −1 ) and the saturation temperature ranging between 35 and 45 °C over the vapor quality range 0.0–1.0. It was found that the experimental heat transfer performance of R1234ze(E) was about 20–45% lower than R32 but 10–30% higher than R410A for saturation temperature 40 °C. The experimental results are compared with some well-known existing prediction methods of condensation of pure refrigerant.