ISSN:0022-1686    

DOI:10.1080/00221688209499490

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688209499491

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688209499492

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688209499493

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

This paper reviews a universal efficiency scaling process for turbomachines of different specific speed nq^ with “hydraulieally smooth” as well as “technically rough” surfaces. Relevant studies are based on model machine characteristics, measurements with individual machine components, and the laws of resistance of technically rough plates. A scaling formula has been derived from these, which is equally suitable for pumps and water turbines. Theoretical and experimental data are in good agreement. The investigations also provide information on the coefficient of equivalence in the smoothrough transition region and on the magnitude of the technical roughness characterizing hydraulieally smooth surfaces. Such data are important to provide information and guidelines for the clarification of questions concerning an economically justifiable extent of surface finishing with which friction losses can be kept within reasonable limits.Technical University, Darmstadt, Fed. Rep. of Germany

ISSN:0022-1686    

DOI:10.1080/00221688209499494

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Transverse mixing under steady conditions is studied by introducing the mass streamline as the streamline of the mass density vector field. The two equations derived for it allow calculations of the concentration field, or the dispersion coefficient under different assumptions if the concentrations are given. The correctness of numerical methods developed was tested. Tracer studies have been performed on five different streams (Q = 0.25 - 2000 m3s-1) and data published have also been used. The methods based on the concept of mass streamline were applied, and the results were compared to observed concentrations. The limitations of the two-dimensional treatment have been examined finally. Key words: streams, channels, hydraulics, diffusion, dispersion, turbulence, water, water pollution, numerical methods.

ISSN:0022-1686    

DOI:10.1080/00221688209499495

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0022-1686    

DOI:10.1080/00221688209499489

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor