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Blake P Tullis - One of the best experts on this subject based on the ideXlab platform.
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Entrance Loss Coefficients and Inlet Control Head–Discharge Relationships for Buried-Invert Culverts
Journal of Irrigation and Drainage Engineering-asce, 2008Co-Authors: Blake P Tullis, D S Anderson, S C RobinsonAbstract:In current practice, entrance Loss coefficients and Inlet control head–discharge relationships for buried-invert culverts designed for fish passage applications are either ignored or approximated using traditional culvert design data due to a lack of data specific to these alternative culvert geometries. This study experimentally determined entrance Loss coefficients and Inlet control head–discharge relationships for circular culverts with invert burial depths of 20, 40, and 50% and an elliptical culvert with 50% invert burial depth. In general, the Inlet Loss coefficients for buried-invert culverts were higher than for traditional culverts of the same cross-sectional shape without invert burial. The influence of approach flow conditions (ponded or channelized) on Inlet Loss coefficients and Inlet control head–discharge relationships was also investigated. This paper outlines the experimental methods used to determine entrance Loss coefficients and Inlet control head–discharge regression constants relativ...
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entrance Loss coefficients and Inlet control head discharge relationships for buried invert culverts
Journal of Irrigation and Drainage Engineering-asce, 2008Co-Authors: Blake P Tullis, D S Anderson, S C RobinsonAbstract:In current practice, entrance Loss coefficients and Inlet control head–discharge relationships for buried-invert culverts designed for fish passage applications are either ignored or approximated using traditional culvert design data due to a lack of data specific to these alternative culvert geometries. This study experimentally determined entrance Loss coefficients and Inlet control head–discharge relationships for circular culverts with invert burial depths of 20, 40, and 50% and an elliptical culvert with 50% invert burial depth. In general, the Inlet Loss coefficients for buried-invert culverts were higher than for traditional culverts of the same cross-sectional shape without invert burial. The influence of approach flow conditions (ponded or channelized) on Inlet Loss coefficients and Inlet control head–discharge relationships was also investigated. This paper outlines the experimental methods used to determine entrance Loss coefficients and Inlet control head–discharge regression constants relativ...
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Experimentally Determined Inlet Loss Coefficients for Buried-Invert, Circular Culverts
World Environmental and Water Resource Congress 2006, 2006Co-Authors: D S Anderson, Blake P TullisAbstract:In current practice, Inlet Loss coefficients for buried-invert culverts are either ignored or approximated using traditional culvert design data due to a lack of data specific to fish passage culvert geometries. This study included the experimental determination of Inlet Loss coefficients for a circular culvert with an invert burial depth of 50%. Culvert inverts are buried when a simulated streambed is desired in the culvert for fish passage applications. This paper outlines the experimental methods used to determine Inlet Loss coefficients relative to fish passage culvert geometries and presents the data relevant to the hydraulic design and evaluation of these culverts.
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Hydraulic Characteristics of Buried-Invert, Elliptical Culverts
Transportation Research Record, 2005Co-Authors: Blake P Tullis, S. Collin Robinson, J C YoungAbstract:In response to recent and ongoing adaptation of culvert designs to environmentally sensitive installations, Inlet Loss coefficients and Inlet control flow performance data are presented that are specific to environmentally sensitive culvert geometries. A common practice for such culvert designs is to bury the culvert inverts and create a simulated streambed through the culvert. Common cross-sectional geometries of such culverts typically include circular, elliptical, or pipe arch. These buried- or depressed-invert culverts create Inlet geometries for which Inlet Loss information and Inlet control flow performance curves have not been developed. Regardless of the method used to design environmentally sensitive culverts, the ability of the culvert to pass the design flood must be determined. In an effort to provide such information, an elliptical smooth-wall culvert with an invert burial depth of 50% was tested under various conditions (e.g., various end treatments, Inlet and outlet control, submerged and unsubmerged Inlet conditions, and ponded and channelized approach flow conditions) to determine the Inlet Loss coefficient and flow performance curve characteristics. The test results show that the Inlet Loss coefficient is relatively independent of both Reynolds number and the ratio of the distance from the Inlet invert to the upstream total energy grade line to the culvert diameter (HW/D) and that the Inlet Loss coefficients for the elliptical culvert with 50% burial depth are approximately equal to the published coefficients for traditional culvert Inlets. The Inlet control data adapt well to the Form 1 and Form 2 unsubmerged and the submerged equations recommended by the Federal Highway Administration.
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Hydraulic Characteristics of Buried-Invert Elliptical Culverts
Transportation Research Record: Journal of the Transportation Research Board, 2005Co-Authors: Blake P Tullis, S. Collin Robinson, J C YoungAbstract:In response to recent and ongoing adaptation of culvert designs to environmentally sensitive installations, Inlet Loss coefficients and Inlet control flow performance data are presented that are specific to environmentally sensitive culvert geometries. A common practice for such culvert designs is to bury the culvert inverts and create a simulated streambed through the culvert. Common cross-sectional geometries of such culverts typically include circular, elliptical, or pipe arch. These buried- or depressed-invert culverts create Inlet geometries for which Inlet Loss information and Inlet control flow performance curves have not been developed. Regardless of the method used to design environmentally sensitive culverts, the ability of the culvert to pass the design flood must be determined. In an effort to provide such information, an elliptical smooth-wall culvert with an invert burial depth of 50% was tested under various conditions (e.g., various end treatments, Inlet and outlet control, submerged and unsubmerged Inlet conditions, and ponded and channelized approach flow conditions) to determine the Inlet Loss coefficient and flow performance curve characteristics. The test results show that the Inlet Loss coefficient is relatively independent of both Reynolds number and the ratio of the distance from the Inlet invert to the upstream total energy grade line to the culvert diameter ( HW/ D) and that the Inlet Loss coefficients for the elliptical culvert with 50% burial depth are approximately equal to the published coefficients for traditional culvert Inlets. The Inlet control data adapt well to the Form 1 and Form 2 unsubmerged and the submerged equations recommended by FHWA.
Detlev G. Kröger - One of the best experts on this subject based on the ideXlab platform.
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A numerical investigation of vapor flow in large air-cooled condensers
Applied Thermal Engineering, 2017Co-Authors: Michael Owen, Detlev G. KrögerAbstract:Abstract A numerical simulation method – using a combination of computational fluid dynamics (CFD), numerical and analytical methods – for investigating the nature of the vapor flow distribution in the primary condensers of a large ACC is presented. A definite trend in Inlet Loss coefficient distribution through the heat exchanger bundles is identified. The vapor flow distribution is found to be influenced by the Inlet Loss coefficients to such an extent that the flow distribution appears to not conform to the expected pattern typical of parallel or reverse flow manifolds. This non-uniform axial distribution of vapor amongst the primary condenser tubes places an additional demand on the dephlegmator that cannot be overlooked. This verified simulation method can be applied during the design phase of an ACC to improve the steam-side performance of these systems.
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Computational Fluid Dynamics Analysis of Cooling Tower Inlets
Journal of Fluids Engineering, 2011Co-Authors: H. C. R. Reuter, Detlev G. KrögerAbstract:Cooling tower Inlet Losses are the flow Losses or viscous dissipation of mechanical energy affected directly by the cooling tower Inlet design, which according to the counterflow natural draft wet-cooling tower performance analysis example given in Kroger (Kroger, 2004, Air-Cooled Heat Exchangers and Cooling Towers: Thermal-Flow Performance Evaluation, Pennwell Corp., Tulsa, OK), can be more than 20% of the total cooling tower flow Losses. Flow separation at the lower edge of the shell results in a vena contracta with a distorted Inlet velocity distribution that causes a reduction in effective fill or heat exchanger flow area. In this paper, a two-dimensional (axi-symmetric) computational fluid dynamic (CFD) model is developed using the commercial CFD code ANSYS FLUENT, to simulate the flow patterns, Loss coefficients and effective flow diameter of circular natural draft cooling tower Inlets under windless conditions. The CFD results are compared with axial velocity profile data, tower Inlet Loss coefficients and effective diameters determined experimentally by Terblanche (Terblanche, 1993, "Inlaatverliese by Koeltorings," M. Sc. Eng. thesis, Stellenbosch University, Stellenbosch, South Africa) on a cylindrical scale sector model as well as applicable empirical relations found in Kroger, determined using the same experimental apparatus as Terblanche. The validated CFD model is used to investigate the effects of Reynolds number, shell-wall thickness, shell wall inclination angle, fill Loss coefficient, fill type, Inlet diameter to Inlet height ratio and Inlet geometry on the flow patterns, Inlet Loss coefficient and effective diameter of full-scale cooling towers. Ultimately, simple correlations are proposed for determining the cooling tower Inlet Loss coefficient and Inlet effective flow diameter ratio of full-scale cooling towers excluding the effect of rain zones and the structural supports around the cooling tower entrance.
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Inlet Losses in Counterflow Wet-Cooling Towers
Journal of Engineering for Gas Turbines and Power, 2001Co-Authors: E. De Villiers, Detlev G. KrögerAbstract:The Inlet Loss coefficients for dry, isotropically packed, circular and rectangular counterflow cooling towers are determined experimentally and empirical correlations are formulated to fit this data. Computational fluid dynamics is used to investigate the dependence of the Inlet Loss coefficient on the rain zone characteristics. The rain zone generally dampens the Inlet Loss, but the coupling is indirect and involves a large number of dependent variables. The numerical model is validated by means of experimental data for dry towers and it is found that the degree of accuracy achieved for circular towers exceeds that for rectangular towers. Consequently, the correlation derived to predict this occurrence for circular towers can be applied more confidently than its rectangular counterpart.
D G Kroger - One of the best experts on this subject based on the ideXlab platform.
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critical evaluation of solar chimney power plant performance
Solar Energy, 2006Co-Authors: Johannes P Pretorius, D G KrogerAbstract:This paper evaluates the influence of a recently developed convective heat transfer equation, more accurate turbine Inlet Loss coefficient, quality collector roof glass and various types of soil on the performance of a large scale solar chimney power plant. Results indicate that the new heat transfer equation reduces plant power output considerably. The effect of a more accurate turbine Inlet Loss coefficient is insignificant, while utilizing better quality glass enhances plant power production. Models employing Limestone and Sandstone soil produce virtually similar results to a Granite-based model. The plant collector height is found to differ from previously obtained optimal values.
S C Robinson - One of the best experts on this subject based on the ideXlab platform.
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Entrance Loss Coefficients and Inlet Control Head–Discharge Relationships for Buried-Invert Culverts
Journal of Irrigation and Drainage Engineering-asce, 2008Co-Authors: Blake P Tullis, D S Anderson, S C RobinsonAbstract:In current practice, entrance Loss coefficients and Inlet control head–discharge relationships for buried-invert culverts designed for fish passage applications are either ignored or approximated using traditional culvert design data due to a lack of data specific to these alternative culvert geometries. This study experimentally determined entrance Loss coefficients and Inlet control head–discharge relationships for circular culverts with invert burial depths of 20, 40, and 50% and an elliptical culvert with 50% invert burial depth. In general, the Inlet Loss coefficients for buried-invert culverts were higher than for traditional culverts of the same cross-sectional shape without invert burial. The influence of approach flow conditions (ponded or channelized) on Inlet Loss coefficients and Inlet control head–discharge relationships was also investigated. This paper outlines the experimental methods used to determine entrance Loss coefficients and Inlet control head–discharge regression constants relativ...
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entrance Loss coefficients and Inlet control head discharge relationships for buried invert culverts
Journal of Irrigation and Drainage Engineering-asce, 2008Co-Authors: Blake P Tullis, D S Anderson, S C RobinsonAbstract:In current practice, entrance Loss coefficients and Inlet control head–discharge relationships for buried-invert culverts designed for fish passage applications are either ignored or approximated using traditional culvert design data due to a lack of data specific to these alternative culvert geometries. This study experimentally determined entrance Loss coefficients and Inlet control head–discharge relationships for circular culverts with invert burial depths of 20, 40, and 50% and an elliptical culvert with 50% invert burial depth. In general, the Inlet Loss coefficients for buried-invert culverts were higher than for traditional culverts of the same cross-sectional shape without invert burial. The influence of approach flow conditions (ponded or channelized) on Inlet Loss coefficients and Inlet control head–discharge relationships was also investigated. This paper outlines the experimental methods used to determine entrance Loss coefficients and Inlet control head–discharge regression constants relativ...
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Part 3: Hydrology, Hydraulics, and Water Quality: Hydraulic Characteristics of Buried-Invert Elliptical Culverts
Transportation Research Record: Journal of the Transportation Research Board, 2005Co-Authors: Blake P Tullis, S C Robinson, J C YoungAbstract:In response to recent and ongoing adaptation of culvert designs to environmentally sensitive installations, Inlet Loss coefficients and Inlet control flow performance data are presented that are specific to environmentally sensitive culvert geometries. A common practice for such culvert designs is to bury the culvert inverts and create a simulated streambed through the culvert. Common cross-sectional geometries of such culverts typically include circular, elliptical, or pipe arch. These buried-or depressed-invert culverts create Inlet geometries for which Inlet Loss information and Inlet control flow performance curves have not been developed. Regardless of the method used to design environmentally sensitive culverts, the ability of the culvert to pass the design flood must be determined. In an effort to provide such information, an elliptical smooth-wall culvert with an invert burial depth of 50% was tested under various conditions (e.g., various end treatments, Inlet and outlet control, submerged and un...
J C Young - One of the best experts on this subject based on the ideXlab platform.
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Hydraulic Characteristics of Buried-Invert, Elliptical Culverts
Transportation Research Record, 2005Co-Authors: Blake P Tullis, S. Collin Robinson, J C YoungAbstract:In response to recent and ongoing adaptation of culvert designs to environmentally sensitive installations, Inlet Loss coefficients and Inlet control flow performance data are presented that are specific to environmentally sensitive culvert geometries. A common practice for such culvert designs is to bury the culvert inverts and create a simulated streambed through the culvert. Common cross-sectional geometries of such culverts typically include circular, elliptical, or pipe arch. These buried- or depressed-invert culverts create Inlet geometries for which Inlet Loss information and Inlet control flow performance curves have not been developed. Regardless of the method used to design environmentally sensitive culverts, the ability of the culvert to pass the design flood must be determined. In an effort to provide such information, an elliptical smooth-wall culvert with an invert burial depth of 50% was tested under various conditions (e.g., various end treatments, Inlet and outlet control, submerged and unsubmerged Inlet conditions, and ponded and channelized approach flow conditions) to determine the Inlet Loss coefficient and flow performance curve characteristics. The test results show that the Inlet Loss coefficient is relatively independent of both Reynolds number and the ratio of the distance from the Inlet invert to the upstream total energy grade line to the culvert diameter (HW/D) and that the Inlet Loss coefficients for the elliptical culvert with 50% burial depth are approximately equal to the published coefficients for traditional culvert Inlets. The Inlet control data adapt well to the Form 1 and Form 2 unsubmerged and the submerged equations recommended by the Federal Highway Administration.
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Hydraulic Characteristics of Buried-Invert Elliptical Culverts
Transportation Research Record: Journal of the Transportation Research Board, 2005Co-Authors: Blake P Tullis, S. Collin Robinson, J C YoungAbstract:In response to recent and ongoing adaptation of culvert designs to environmentally sensitive installations, Inlet Loss coefficients and Inlet control flow performance data are presented that are specific to environmentally sensitive culvert geometries. A common practice for such culvert designs is to bury the culvert inverts and create a simulated streambed through the culvert. Common cross-sectional geometries of such culverts typically include circular, elliptical, or pipe arch. These buried- or depressed-invert culverts create Inlet geometries for which Inlet Loss information and Inlet control flow performance curves have not been developed. Regardless of the method used to design environmentally sensitive culverts, the ability of the culvert to pass the design flood must be determined. In an effort to provide such information, an elliptical smooth-wall culvert with an invert burial depth of 50% was tested under various conditions (e.g., various end treatments, Inlet and outlet control, submerged and unsubmerged Inlet conditions, and ponded and channelized approach flow conditions) to determine the Inlet Loss coefficient and flow performance curve characteristics. The test results show that the Inlet Loss coefficient is relatively independent of both Reynolds number and the ratio of the distance from the Inlet invert to the upstream total energy grade line to the culvert diameter ( HW/ D) and that the Inlet Loss coefficients for the elliptical culvert with 50% burial depth are approximately equal to the published coefficients for traditional culvert Inlets. The Inlet control data adapt well to the Form 1 and Form 2 unsubmerged and the submerged equations recommended by FHWA.
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Part 3: Hydrology, Hydraulics, and Water Quality: Hydraulic Characteristics of Buried-Invert Elliptical Culverts
Transportation Research Record: Journal of the Transportation Research Board, 2005Co-Authors: Blake P Tullis, S C Robinson, J C YoungAbstract:In response to recent and ongoing adaptation of culvert designs to environmentally sensitive installations, Inlet Loss coefficients and Inlet control flow performance data are presented that are specific to environmentally sensitive culvert geometries. A common practice for such culvert designs is to bury the culvert inverts and create a simulated streambed through the culvert. Common cross-sectional geometries of such culverts typically include circular, elliptical, or pipe arch. These buried-or depressed-invert culverts create Inlet geometries for which Inlet Loss information and Inlet control flow performance curves have not been developed. Regardless of the method used to design environmentally sensitive culverts, the ability of the culvert to pass the design flood must be determined. In an effort to provide such information, an elliptical smooth-wall culvert with an invert burial depth of 50% was tested under various conditions (e.g., various end treatments, Inlet and outlet control, submerged and un...