Download or read book An Experimental Study of Wall Shear Stress on Distributed Rough Surfaces in a Turbulent Boundary Layer written by William J. Dalling and published by . This book was released on 2003 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Study of Turbulent Boundary Layer on Rough Walls written by C. K. Liu and published by . This book was released on 1966 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental data are presented on flow structure, mean, and fluctuating velocities in turbulent boundary layers over a family of flat surfaces with transverse roughness elements made of square bars of variable spacing. All flows were incompressible and had zero streamwise pressure gradient. The flow structures are described for surfaces extending from hydraulically smooth to fully rough. A distinct flow pattern is observed in the wall region for each of four cases: smooth, skimming, wake-interference and isolated-roughness flow. Maximum roughness was observed with a ratio of gap to bar width of approximately 11. The most obvious effect of an increase in surface roughness is the distinct increase of turbulence production and the concomittant increase in the value of eddy viscosity. It is shown that this increase in eddy viscosity increases the total thickness of the layer in the same way that an increase in molecular viscosity would do in a laminar layer. The normalization of eddy viscosity for the outer portion of the layer as suggested by Clauser is found to apply to the rough surfaces studied. (Author).
Download or read book Experimental Study of a Three dimensional Shear driven Turbulent Boundary Layer with Streamwise Adverse Pressure Gradient written by David Michael Driver and published by . This book was released on 1989 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Boundary Layer an Experimental Study of the Transport of Momentum and Heat with the Effect of Roughness written by Stanford University. Thermosciences Division. Thermosciences Division and published by . This book was released on 1975 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of High Speed Boundary Layers with Wall Roughness written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive investigation of the influence of surface roughness on the mean and turbulent flow properties of a high-speed turbulent boundary layer flow was performed. Six wall topologies, including a smooth and five rough surfaces consisting of three random sand-grain plates and two uniformly machined plates (k = 0 - 1.7 mm), were tested at three high Reynolds number (Re/m = 2 x lO (exp 7) Mach numbers (0.22, 0.65 and 2.75) . Mean flow measurements included surveys of the velocity and density. Turbulence quantities included measurements of the kinematic velocity turbulence intensities, mass flux turbulence intensities, kinematic Reynolds shear stress, compressible Reynolds shear stress, density-transverse-velocity fluctuation correlation, velocity spectra, auto-correlations, micro- and integral-scales and turbulent structure angles. Numerical simulations included evaluating three algebraic turbulence models with a boundary layer program. A three-year program was performed.
Download or read book Open Channel Turbulent Boundary Layers and Wall Jets on Rough Surfaces written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For many industrial and environmental flows, the momentum and convective heat transfer rates at the surface are determined by the turbulence structure in the near-wall region. Although many flows of practical interest occur on rough surfaces, our understanding and ability to predict rough wall turbulent flows lags far behind the corresponding technology for smooth surfaces. This provides reasonable grounds for additional refined rough wall measurements with the expectation of improving our physical understanding of practically relevant turbulent flows. This thesis reports an experimental investigation of wall roughness effects on the characteristics of turbulent boundary layers and wall jets. The measurements are obtained for smooth wall and three different roughness elements using a laser-Doppler anemometer. An insightful presentation of the results requires that the correct scaling laws must be used. In the case of the turbulent boundary layer, the appropriateness of the log law proposed by Millikan (1938) to model the overlap region of the mean flow and the power laws proposed by Barenblatt (1993) and George and Castillo (1997) is compared. The boundary layer results show that the theory proposed by George and Castillo (1997) has important advantages over the log law in modeling the mean velocity profiles as well as predicting the wall shear stress. The results also show that wall roughness increases the turbulence fluctuations and transport terms, which suggests that rough wall turbulence models must explicitly account for roughness effects in order to predict the mixing characteristics accurately. This promises to provide significant challenges to rough wall turbulence models. The wall jet results show that wall roughness increases the inner layer thickness but the jet half-width does not show any important sensitivity to surface roughness. The spread rates for the jet half-width are higher than the values obtained in earlier measurements. This may be attribute.
Download or read book Hydraulic Research in the United States 1970 written by United States. National Bureau of Standards and published by . This book was released on 1971 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research in Progress written by and published by . This book was released on 1965 with total page 1194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence in Open Channel Flows written by Hiroji Nakagawa and published by Routledge. This book was released on 2017-10-02 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of open channel turbulence, focusing especially on certain features stemming from the presence of the free surface and the bed of a river. Part one presents the statistical theory of turbulence; Part two addresses the coherent structures in open-channel flows and boundary layers.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report written by United States. National Bureau of Standards and published by . This book was released on 1968 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Boundary Layer and Free Shear Flows written by American Society of Mechanical Engineers. Fluids Engineering Division. Summer Meeting and published by . This book was released on 1994 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Distribution of Boundary Shear Stresses in Curved Trapezoidal Channels written by Arthur T. Ippen and published by . This book was released on 1960 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Current Hydraulic Laboratory Research in the United States written by and published by . This book was released on 1970 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulic Research in the United States written by and published by . This book was released on 1964 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
