head-discharge relationship of flumes: energy loss versus boundary layer

نویسندگان

matthieu dufresne

josé vazquez

چکیده

long-throated flumes are measurement structures often used in water and wastewater systems to determine the flow discharge. the head-discharge relationship of long-throated flumes is traditionally determined following the critical flow theory and the boundary layer concept. after a review of the traditional approach and an analysis of the approximate assumptions of the boundary layer approach, this study revisits the energy loss approach as an alternative to the questionable boundary layer concept for the determination of the discharge in long-throated flumes. computational fluid dynamics (cfd) is used for determining the kinetic energy correction coefficient and the piezometric energy correction coefficient along the throat of the flume (especially in the critical section); cfd is also used for locating the critical section and determining the energy loss between the measurement section and the critical section. a new method based on the kinetic energy correction coefficient, the piezometric energy correction coefficient and the energy loss between the measurement section and the control section is proposed. a step-by-step procedure is given for the head-discharge calculation. it appears that the proposed alternative is a simple and promising method to accurately determine the discharge coefficient.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Stepped Spillway Performance: Study of the Pressure and Turbulent Kinetic Energy versus Discharge and Slope

In the present study, flow over flat and pooled stepped spillways was simulated three dimensionally. The VOF method and k- ε (RNG) turbulent model was used to simulate the flow over the stepped spillway. The results indicated that the numerical model was acceptably capable of simulating the flow over the pooled and flat stepped spillways for different discharges. Following that, the effect of d...

متن کامل

Approximate discharge for constant head test with recharging boundary.

The calculation of the discharge to a constant drawdown well or tunnel in the presence of an infinite linear constant head boundary in an ideal confined aquifer usually relies on the numerical inversion of a Laplace transform solution. Such a solution is used to interpret constant head tests in wells or to roughly estimate ground water inflow into tunnels. In this paper, a simple approximate so...

متن کامل

Riesz-Transforms Versus Derivatives: On the Relationship Between the Boundary Tensor and the Energy Tensor

Traditionally, quadrature filters and derivatives have been considered as alternative approaches to low-level image analysis. In this paper we show that there actually exist close connections: We define the quadrature-based boundary tensor and the derivative-based gradient energy tensor which exhibit very similar behavior. We analyse the reason for this and determine how to minimize the differe...

متن کامل

Wave Propagation at the Boundary Surface of Elastic Layer Overlaying a Thermoelastic Without Energy Dissipation Half-space

The present investigation is to study the surface wave propagation at imperfect boundary between an isotropic thermoelastic without energy dissipation half-space and an isotropic elastic layer of finite thickness. The penetration depth of longitudinal, transverse, and thermal waves has been obtained. The secular equation for surface waves in compact form is derived after developing the mathemat...

متن کامل

Influence of Afterbody and Boundary Layer on Cavitating Flow

The characteristics of a cavitation water tunnel test setup and the experiments of cavitation around different models are given in this paper. Models of test are formed from combination of head and variable length afterbody. The experiments are performed initially with the smooth head and then with the roughened head. Cavitation initiates both in the wake and after the head. If the nose of mode...

متن کامل

Nvestigation of a Boundary Layer Problem for Perturbed Cauchy-Riemann Equation with Non-local Boundary Condition

Boundary layer problems (Singular perturbation problems) more have been applied for ordinary differential equations. While this theory for partial differential equations have many applications in several fields of physics and engineering. Because of complexity of limit and boundary behavior of the solutions of partial differential equations these problems considered less than ordinary case. In ...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید


عنوان ژورنال:
journal of applied research in water and wastewater

ناشر: razi university

ISSN

دوره 1

شماره 2 2014

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023