scholarly journals The Uniformity of Nonuniform Flow

CSA News ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 9-13
Author(s):  
DJ McCauley
Keyword(s):  
Nonuniform Flow

Nonuniform flow in soft glasses of colloidal rods

2017 ◽  
Vol 2 (4) ◽  
Author(s):  
J. K. G. Dhont ◽  
K. Kang ◽  
H. Kriegs ◽  
O. Danko ◽  
J. Marakis ◽  
...  
Keyword(s):  
Nonuniform Flow ◽  
Soft Glasses ◽  
Colloidal Rods

Dune-scale cross-strata across the fluvial-deltaic backwater regime: Preservation potential of an autogenic stratigraphic signature

Geology ◽  
2020 ◽  
Vol 48 (12) ◽  
pp. 1144-1148
Author(s):  
Chenliang Wu ◽  
Jeffrey A. Nittrouer ◽  
Travis Swanson ◽  
Hongbo Ma ◽  
Eric Barefoot ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Mississippi River ◽  
Nonuniform Flow ◽  
Hydrodynamic Conditions ◽  
Flow Conditions ◽  
Bed Topography ◽  
Fundamental Building Block ◽  
Bed Form ◽  
Spatially Varying ◽  
Topography Data

Abstract Dune-scale cross-beds are a fundamental building block of fluvial-deltaic stratigraphy and have been recognized on Earth and other terrestrial planets. The architecture of these stratal elements reflects bed-form dynamics that are dependent on river hydrodynamic conditions, and previous work has documented a multitude of scaling relationships to describe the morphodynamic interactions between dunes and fluid flow. However, these relationships are predicated on normal flow conditions for river systems and thus may be unsuitable for application in fluvial-deltaic settings that are impacted by nonuniform flow. The ways in which dune dimensions vary systematically due to the influence of reach-averaged, nonuniform flow, and how such changes may be encoded in dune cross-strata, have not been investigated. Herein, we explored the influence of backwater flow on dune geometry in a large modern fluvial channel and its implications for interpretation of systematic variability in dune cross-strata in outcrop-scale stratigraphy. This was accomplished by analyzing high-resolution channel-bed topography data for the lowermost 410 km of the Mississippi River, which revealed that dune size increases to a maximum before decreasing toward the river outlet. This spatial variability coincides with enhanced channel-bed aggradation and decreasing dune celerity, which arise due to backwater hydrodynamics. An analytical model of bed-form stratification, identifying spatial variability of cross-set thickness, indicates a prominent downstream decrease over the backwater region. These findings can be used to inform studies of ancient fluvial-deltaic settings, by bolstering assessments of proximity to the marine terminus and associated spatially varying paleohydraulics.

Experimental and Theoretical Analysis of Transient Response of Plate Heat Exchangers in Presence of Nonuniform Flow Distribution

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
N. Srihari ◽  
Sarit K. Das
Keyword(s):  
Steady State ◽  
Heat Exchangers ◽  
Sudden Change ◽  
Temperature Response ◽  
Flow Distribution ◽  
Transient Temperature ◽  
Nonuniform Flow ◽  
Flow Rates ◽  
Plate Heat ◽  
Flow Maldistribution

Transient analysis helps us to predict the behavior of heat exchangers subjected to various operational disturbances due to sudden change in temperature or flow rates of the working fluids. The present experimental analysis deals with the effect of flow distribution on the transient temperature response for U-type and Z-type plate heat exchangers. The experiments have been carried out with uniform and nonuniform flow distributions for various flow rates. The temperature responses are analyzed for various transient characteristics, such as initial delay and time constant. It is also possible to observe the steady state characteristics after the responses reach asymptotic values. The experimental observations indicate that the Z-type flow configuration is more strongly affected by flow maldistribution compared to the U-type in both transient and steady state regimes. The comparison of the experimental results with numerical solution indicates that it is necessary to treat the flow maldistribution separately from axial thermal dispersion during modeling of plate heat exchanger dynamics.

The Unsteady Loading on a Marine Propeller in a Nonuniform Flow

1964 ◽  
Vol 8 (05) ◽  
pp. 29-38
Author(s):  
Michael D. Greenberg
Keyword(s):  
Free Stream ◽  
Marine Propeller ◽  
Nonuniform Flow ◽  
Surface Integral ◽  
Practical Applications ◽  
Vortex Model ◽  
Surface Integral Equation ◽  
Lifting Surface ◽  
Finite Wing ◽  
Unsteady Loading

The lifting-surface integral equation governing the unsteady loading on a marine propeller in a nonuniform free stream is derived using a classical vortex model. The induced downwash is split into a part corresponding to a locally tangent flat finite wing and wake, plus parts corresponding to the effects of the "helicoidal deviation" from this, of the true blade and wake, and the interference from the other blades and their wakes. Strip-type approximations are tolerated on these terms while a lifting-surface formulation is retained for the dominant finite flat-wing portion. A simple numerical example is carried out and these effects are indeed found to be quite small; so small, in fact, that it may suffice to retain only the flat finite-wing terms in practical applications.

A Note on the Secondary Vortex Caused by a Thin Foil in a Nonuniform Flow

1988 ◽  
Vol 32 (01) ◽  
pp. 80-81
Author(s):  
B. Yim
Keyword(s):  
Thin Foil ◽  
Uniform Flow ◽  
Secondary Vortex ◽  
Nonuniform Flow ◽  
Vortex Strength ◽  
Finite Span ◽  
Trailing Vortices

WHEN A finite span lifting wing is located in a uniform flow, trailing vortices are generated by the wing. It is well known from the Kelvin theorem that the trailing vortex strength is proportional to the spanwise slope of the bound vortex distribution. When the wing is located in a nonuniform flow, the problem becomes complex. Such flow has been dealt with by Vandry [1], 2 Karman and Tshen [2], Honda [8], and Smith [4]. It has been found that this flow has an extra trailing vortex created by the interaction between the nonuniform flow and the wing. This extra vortex is called the secondary vortex and has been studied extensively in connection with the theory of turbomachinery.

scholarly journals Error Analysis of Integrated Absorbance for TDLAS in a Nonuniform Flow Field

2021 ◽  
Vol 11 (22) ◽  
pp. 10936
Author(s):  
Renjie Li ◽  
Fei Li ◽  
Xin Lin ◽  
Xilong Yu
Keyword(s):  
Diode Laser ◽  
Line Shape ◽  
Shape Function ◽  
Tunable Diode Laser ◽  
Nonuniform Flow ◽  
Laser Absorption ◽  
Fitting Method ◽  
Diagnosis Method ◽  
Diode Laser Absorption ◽  
General Method

As an effective optical diagnosis method, tunable diode-laser absorption spectroscopy (TDLAS) has increasingly moved to examine nonuniform flows, such as two-dimensional combustion diagnosis. To investigate the effect of nonuniformity along the line of sight in a measurement using TDLAS, the integrated absorbance (IA, the key intermediate quantity in TDLAS) error was quantified. The error distribution is obtained from the line-shape parameters through the comprehensive analysis of the line-shape function and the fitting method. The effects of the fitting function and the absorption line overlap are also considered. A general method for estimating the error is given. The work illustrates the applicability of TDLAS technology in nonuniform flow fields and provides input parameters for the evaluation of tunable diode laser absorption tomography error.

General Analysis of Longitudinal Dispersion in Nonuniform Flow

1971 ◽  
Vol 7 (6) ◽  
pp. 1511-1521 ◽  
Author(s):  
L. W. Gelhar ◽  
M. A. Collins
Keyword(s):  
General Analysis ◽  
Longitudinal Dispersion ◽  
Nonuniform Flow

Design of High-Speed Propellers for Nonuniform Flow

1970 ◽  
Author(s):  
Richard Hecker
Keyword(s):  
High Speed ◽  
Nonuniform Flow

Propeller Loading-Induced Velocity Field by Means of Unsteady Lifting Surface Theory

1973 ◽  
Vol 17 (03) ◽  
pp. 129-139
Author(s):  
W. R. Jacobs ◽  
S. Tsakonas
Keyword(s):  
Velocity Field ◽  
High Speed ◽  
Pressure Field ◽  
Numerical Procedure ◽  
Nonuniform Flow ◽  
Surface Theory ◽  
Loading Function ◽  
Lifting Surface ◽  
Space Function ◽  
Induced Velocity

An analysis based on the lifting surface theory has been developed for evaluation of the vibratory velocity field induced by the loading of an operating propeller in both uniform and nonuniform inflow fields. The analysis demonstrates that in the case of nonuniform flow the velocity at any field point is made up of a large number of combinations of the frequency constituents of the loading function with those of the space function (propagation or influence function). A numerical procedure has been developed adaptable to a high-speed digital computer (CDC 6600), and the existing program, which evaluates the steady and unsteady propeller loadings, the resulting hydrodynamic forces and moments, and the pressure field, has been extended to include evaluation of the velocity field as well. This program should thus become a highly versatile and useful tool for the ship researcher or designer.

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