Rectangular weir coefficient derivation. 089, while the Cd values for the triangular weir ranged .
Rectangular weir coefficient derivation. Install the suppressed rectangular weir in the channel.
Rectangular weir coefficient derivation The Francis equation has a constant discharge coefficient which facilitates computations without the use of tables. 2 Theory 2. Thus the same formula for discharge over a narrow-crested weir holds good, which was derived from an ordinary weir. 33), which facilitates computations. Here we define triangular notch/weir and we derive an expression for rate of flow thro Statement A: The triangular weir gives less accurate results than a rectangular weir for measuring low discharges. Ghodsian 3 ABSTRACT: To estimate the outflow over a rectangular sharp-crested side weir, the discharge coefficient in the weir equation needs to be known. 5 h 1. 4. A partially contracted weir has B-b between 0 and 4h max A weir is a barrier in an open channel, over which water flows. The discharge through a weir or notch is directly related to the water depth or head (H). The relationship between the discharge coefficient and the Froude number, as well as the ratios of the side weir height and Apr 9, 2023 · 2. 1 < h / L ≤ 0. 81 (m/s 2) - gravity Studio Express uses a standard weir equation for Rectangular Sharp-crested, Compound, Cipolletti, Trapezoidal and Rectangular Broad-crested weirs. 5 Apr 1, 2011 · For a rectangular weir as given in Fig. The discharge coefficient is assumed to represent all effects due to assumptions made in the Nov 19, 2012 · An experimental study is made here to investigate the discharge coefficient for contracted rectangular Sharp crested weirs. The Cd values for the rectangular weir ranged from 0. 1. What height of a rectangular weir must be installed to double the depth? Discharge coefficient of weir may be taken as 0. for a V-notch; for a R-notch: 8. Consider a rectangular notch or weir provided in a channel carrying water as shown in fig. Dec 30, 2014 · The classical head–discharge relation for rectangular sharp-crested weirs is applicable only to free flow conditions, not valid at low head when flow becomes clinging. The water before the weir should be held in a relatively Mar 1, 2015 · For a rectangular weir (Fig. This research was based mainly on laboratory experiments for studying the In the sharp-crested V-notch weir when That, , then: √ (1) (2) where, the Cʹdv is discharge coefficient of sharp-crested V-notch weir when Moreover, the hʹ is the water head over the crest of sharp-crested V-notch weir, θʹ is vortex angle and pʹ3 is the height of sharp-crested V-notch weir. Fluid Mecha A suppressed weir's notch width (b) is equal to the channel width (B); thus, there really isn't a notch - the weir is flat all the way along the top. 2 ft, and H = 0. e. Feb 16, 2017 · The derivation of discharge over a rectangular weir assumes that the flow is steady, uniform, and fully developed. Weir Crest: The edge over which the water flows is the weir crest. R. Rehbock (1929) proposed the following equation for Feb 28, 2024 · In this study, experimental investigations were conducted on rectangular side weirs with different widths and heights. Figure 1 shows a triangular-notch, thin-plate weir installed at the end of a rectangular channel. In order to maintain a hydrostatic pressure distribution above the weir crest, i. 089, while the Cd values for the triangular weir ranged Dec 1, 2017 · Some researchers tested one opening with different diameters. g. 4 ft, P = 1. 6. Equation 1 gives discharge values for rectangular-weir notch lengths of up to 4 feet and depths of flow or head of up to 1. 2 ) depends on the approach velocity and the upstream water level. 01–7. 5. 9m. the weir coefficient of discharge can be obtained using a formula based on a quasi-steady state analysis for the Apr 1, 2011 · The average outflow velocity over the rectangular contracted weir was expressed in terms of the head over weir, the momentum correction coefficient and the ratio between the crest length and the Sep 15, 2023 · The 2A triangular weir is a new type of weir that belongs to the category of weirs with a triangular longitudinal profile. It has been found that Z/H is the most important. Weirs are to be evaluated using the following equation: Q = CLH 3/2 where: Q = Discharge in cfs C = Discharge coefficient from Handbook of Hydraulics, King and Brater, 5th Edition (or comparable) L = Effective length of crest in feet Ce is the effective discharge coefficient H is the head over the weir in ft k is a head correction factor θ is the angle of the V-notch Ce, the effective weir coefficient, and k, the head correction factor, are both functions of only θ if the V-notch weir is fully contracted (P > 2 Hmax & S > 2 Hmax). 0 feet for the expected rate of flow. Consider a rectangular weir with a head on the weir (\(h\)) of 25 meters, a width of the weir (\(b\)) of 20 meters, and a discharge constant (\(C_d\)) of 15. Mar 4, 2018 · The Cd values in a triangular weir were greater than in a rectangular weir. Position the hook gage next to the weir plate and zero the scale at the weir crest elevation. Weir Pond: Portion of the channel immediately upstream from the weir. 0). that flows after the weir, in a trapezoidal weir the Froude number decrease slightly but after that, it increases again downstream. The term suppressed is used to mean that the end contractions, as shown in Figure 2 (c), are suppressed (not present). Dec 1, 2015 · Emiroglu et al. The accuracy of the discharge coefficient is ± 5 percent. 1 (US). 5 ft head over the weir. Borghei,1 M. The common objective of these studies was to investigate the flow behaviour of the weirs and obtain the discharge coefficient. 1 Terms Used. The following facts should be considered when a specific type of weir is selected for a given application. Further A weir is a barrier in an open channel, over which water flows. It also assumes that the velocity of water approaching the weir is negligible and that the water surface is parallel to the crest of the weir. The procedure, results, analysis, and discussion sections present experimental data on flow rates measured for rectangular and triangular weirs. 2 feet and no greater than 2. The accuracy of the discharge coefficient is +5 percent. Based on experimental data for eight sharp-crested rectangular weirs of different sizes, a new method for calculating discharge at the low head bistable and clinging flow regime was proposed in this study. A contracted weir means that the ditch or canal leading up to the weir is wider than the weir opening itself. 5 *(2*g) 0. Few researchers tested more than one opening but with fixed diameters. Measure the upstream channel cross-section width. For example, a weir coefficient (C) of 3. 3 situated in rectangular channels are frequently used in | Find, read and cite all the research you May 22, 2023 · Reverse flow combinations. weir". The derivation of these relationships from the Bernoulli equation is fairly simple Jun 1, 2021 · Keywords: 90° V-notch, weir, discharge coefficient, weir crest height, approach velocity. For the rectangular weir, measure the crest height from the channel bottom. Weirs are to be evaluated using the following equation: Q = CLH 3/2 where: Q = Discharge in cfs Mar 1, 2015 · For a rectangular weir (Fig. 2. This weir has a rectangular opening where the sides are straight up and down. A uniform flow of discharge q per unit width and depth d encounters the sharp-edged weir, whose crest at C is of height P above the bed, such that the head over the weir is H. The Weber number W, which accounts for surface The discharge coefficient for Cipoletti weirs is 3. for 'Free weir flow - reverse gate, throat control, reverse flow', the position of the gate is not physically in which Q = discharge, in cfs, L = length of the weir crest, in ft, and H = head on the weir crest, in ft. Equation 1 has a constant discharge coefficient (3. Consequently, the traditional weir discharge formula in terms of the upstream total head measured relative to the weir crest elevation (H 1 = h 1 +v 1 2 /2g) is defined as follows [3] (3) Q = 2 3 C d b 2 g H 1 1. Example Calculation. (b) Discharge of Cipoletti Weirs Jan 6, 2021 · PDF | On Jan 6, 2021, Farzin Salmasi and others published Discharge Coefficients for Rectangular Broad-Crested Gabion Weirs: Experimental Study | Find, read and cite all the research you need on Aug 17, 2010 · The weir is nothing more than a combination of the energy equation and Froude equation. 50 where H Full-width sharp-edged broad-crested rectangular weir in a horizontal channel of rectangular cross-section (ISO 3846, 2008) is considered. in which Q = the weir discharge; b = the weir length; h = the head on the crest; g = gravitational acceleration; and C d = discharge coefficient. The variables in this equation have the same significance as in the equations for contracted rectangular weirs discussed in section 9. The area of the element is given by, dA = b dy (5-1 The document is a lab report that examines flow over broad-crested weirs. S. Keywords: Trapezoidal Weir, Froude Number, Flow-3D, open–channel flow . Weirs are constructions designed to alter the properties of river flows to provide irrigation demands. In literature this weir is frequently referred to as a rectangular suppressed weir or Rehbock weir. A rectangular channel 6m wide carries 168 lits/min at a depth of 0. flow rate over a suppressed rectangular weir for given head over the weir and weir dimensions. A weir with a sharp upstream corner or edge such that the water springs clear of the crest is a "sharp crested weir". Assuming critical flow fully develops (F = 1) then C = 3. q = flow rate (m 3 /s) h = elevation head on the weir (m) b = width of the weir (m) g = 9. It is clear from the above derivation that C d in Eq. 2a): for a rectangular weir (Figure 9. Front view of the weir plate In ideal case C d should be equal to one, but because of numerous assumptions made in derivation of Equation 1, According to this study, using weir velocity instead of discharge coefficient can lead to a more realistic and accurate calculation of discharge in rectangular weirs. Rectangular Weir. Its simple construction makes it the most popular. H : height above the weir base; b : width of rectangular weir (R-notch); : angle of triangular weir (V-notch); C d: discharge coefficient to account for the effects of simplifying assumptions in the theory, which has to be determined by experiment [9]. The discharge coefficient of the suppressed weir was . Rectangular-Notch Weir . About this video:This video tutorial is all about flow over rectangular notch/weir in detail. For this About this video:This video tutorial is about triangular notch/weir. 07 H 1 /L 0. Solution : The discharge for a broad crested weir is given by, Here, ; ; Then, The depth of the flow required = The velocity of approach is given by, for a triangular weir (Figure 9. The flow is caused by gravitational acceleration g and is characterised by total head over the weir H in the U profile (Fig Dec 12, 2024 · Statement A: The triangular weir gives less accurate results than a rectangular weir for measuring low discharges. Analysis of water surface profile and measurement of head calibration of the weir 2. Feb 23, 2023 · The Cd values in a triangular weir were greater than in a rectangular weir. In the bistable zone To address this concern and evaluate the financial aspect of rectangular labyrinth weirs, a new discharge coefficient (C L) was introduced by Azimi and Seyed Hakim [53] by using weir length (L) instead of channel width (B) in the head-discharge equation (Eq. Example - Discharge Over A Rectangular Weir Problem A weir of 8m long is to be built across a rectangular channel to discharge a flow of 9m3 /s. The current device has the same upstream and downstream slopes as the Mar 1, 2018 · (1)) to estimate discharge coefficient of pivot weir as follows: (1) Q = C a C r C e 2 3 2 g [(h 1 + K h) (b c + K b) − 2 A s cos θ] h 1 + K h where b c is the weir crest width, A s is the cross-section area, h 1 is the upstream head, g is the acceleration of gravity, θ is the weir angle to the horizon and C a, C r, C e, K h, and K b are Dec 1, 2009 · The average outflow velocity over the rectangular contracted weir was expressed in terms of the head over weir, the momentum correction coefficient and the ratio between the crest length and the Aug 25, 2018 · 8. Broad-crested weir: A weir having a horizontal or nearly horizontal crest sufficiently long in the direction of flow. Know the conditions required in order to use the appropriate form of the Francis equation instead of the Kindsvater-Carter equation to calculate the flow rate over a contracted rectangular weir for given head over the weir and weir dimensions. Since weir velocity has a universal distribution pattern, discharge can better be formulated in terms of average weir velocity which can easily be fit empirically. The discharge coefficient is assumed to represent all effects due to assumptions made in the derivation of Eq. . If the maximum depth of water on the upstream side of weir is to be 2m, what should be the height of the weir ? Adopt C d = 0. ( 7. Corresponding simulations were also performed to analyze hydraulic characteristics including the water surface profile, flow velocity, and pressure. From many years sharp crested rectangular weirs has been investigated by many researchers. A - horizontal differential element is taken at a depth y below the free surface. Problem: Consider a contracted rectangular weir in a rectangular channel with B = 6 ft, L = 2. Following the reasoning of these authors, a similar expression could be 77 obtained for a triangular sharp-crested weir (Equation 3): DISCHARGE COEFFICIENT FOR SHARP-CRESTED SIDE WEIR SUBCRITICAL FLOW IN By S. Thus, a coefficient of C d must be added to correct for these effects, resulting in an expression for actual discharge: (2-39) For measurement convenience, the total head, H 1, is replaced with the depth, h 1. Though the discharge coefficient formulation is simpler than for rectangular weirs, its accuracy is not as good - about ±5% (USBR, 1997). Figure 9. 81 m/s²), \(h\) is the head on the weir in meters. 62 Theoretical discharge coefficient relationship for contracted and suppressed rectangular weirs 167 channel. 1. 1) the discharge, Q, may be written in terms of the measured head over the weir, h, the weir width, b and the discharge coefficient, C d [6]: Q = 2 3 C d 2 g b h 3 / 2 where g is the gravitational acceleration. Figure 3 on page 4 illustrates the Aug 1, 1988 · In this relationship, a discharge coefficient is introduced to correct all the effects neglected in the derivation (viscosity, surface tension, velocity head in the approach channel, flow Oct 3, 2024 · \(b\) is the width of the weir in meters, \(g\) is the acceleration due to gravity (9. A weir having a thin edge as the width is termed a sharp-crested weir, whereas one with appreciable width is called a broad-crested weir. (2) is recognized as the discharge coefficient (C d). This head is affected by the condition of the crest, the contraction, the velocity of approaching stream and the elevation of the water surface downstream from the weir. types of weirs will be introduced: The rectangular-notch weir and the V-notch weir. 56. In order to systemically study the effects of upstream and downstream slope coefficients S1 and S2 on overflow discharge coefficient in a Mar 1, 2014 · The dimensionless variable on the left-hand side of Eq. The crest surfaces of the weir notch are plane surfaces which form Dec 1, 2019 · PDF | Full-width sharp-edged broad-crested rectangular weirs in the range 0. For a weir to be fully contracted, (B-b) must be greater than 4h max, where h max is the maximum expected head on the weir (USBR, 1997). Hence, the weir equation represents the energy of rectangular flow Q with some Froude F. Jalili,2 and M. For finding a discharge of water flowing over the weir or notch, consider an elementary horizontal strip of Rectangular notch: It takes its name from the shape of its notch. Weirs are to be evaluated using the following equation: Q = CLH 3/2 where: Q = Discharge in cfs Rectangular short-crested weirs are widely used for simple structure and high discharge capacity. The discharge equation for the rectangular-notch weir is: Figure 3 . Given, L = 8 m Q = 9 m 3 /s Depth of water = 2m C d = 0. When the crest is "broad", the streamlines become parallel to the crest invert and the pressure distribution above the crest The "weir equation" is a relationship linking the volumetric flow rate above a weir crest to the upstream reservoir level and weir crest geometry. 1 Description of the weir The broad-crested weir has a definite crest length in the direction of flow. Broad Crested Weir Coefficient of Discharge, C d also called Weir Discharge Coefficient C w C w depends upon Weber number W, Reynolds number R and weir geometry (Z/H, L, surface roughness, sharpness of edges etc). 40 + 0. 66 in SI units. For suppressed rectangular weir, discharge equation can be derived and is given below[22]: 𝑄= 2 3 Oct 27, 2016 · Rectangular and Triangular Weirs 5 PART B: TRIANGULAR WEIRS V-notch weirs are among the most accurate open channel devices for measuring discharge. the lower weir crest and step height of broad-crested weirs with rectangular compound cross section on the values of the discharge coefficient (Cd) and the approach velocity coefficient. nel. Jul 2, 2013 · L = length of weir crest in ft h1 = head on weir crest in ft The accuracy of measurements obtained by use of Cipoletti weirs and the above equation is considerably less than that obtainable with suppressed rectangular or V-notch weirs (Shen, 1959). A total of 112 experiments were performed covering a range of weir vertex angles (from 30° to 90°), crest elevations (8 or 10 cm), and discharges (0. If you were to derive it, you'd find that C is a function of only the Froude number and gravity. Consider the flow through a rectangular notch or sharpcrested weir as shown in Figure 8- 1. 415*(L-0. Let, H = head of water over the crest and L = Length of the notch or weir. The flow rate measurement in a rectangular weir is based on the Bernoulli Equation principles and can be expressed as: q = 2/3 c d b (2 g) 1/2 h 3/2 (1) where. both the type of weir to be used and the dimensions of the weir. 068 to 0. (4-38), K is the flow coefficient of the weir and is given as K = 0. This is the oldest type of weir now in use. 2b): where: Q : flow rate; H : height above the weir base; b : width of rectangular weir (R-notch);: angle of triangular weir (V-notch); C d: discharge coefficient to account for the effects of simplifying assumptions in the theory, which has to be determined by experiment [9]. 00 in English Units would be 1. The discharge of a V-notch weir increases more rapidly with the head than in the case of a horizontal crested weir (rectangular or trapezoidal) so for the same maximum capacity, it can measure much smaller discharges. But both share the same discharge coefficient (Cd) of 0. To correct for neglecting the velocity head at the measuring station, a velocity coefficient, C v, must be added, resulting in: (2-40) Mar 30, 2020 · #Dischargeoverrectangularnotch #Rectanglenotch #NotchesDischarge over a Rectangular Notch is educational video for better understanding of notch. 2: (a) Triangular weir, (b) Rectangular weir. 5 where b is the weir opening width, C d is the discharge coefficient, h is the head over the weir crest, and g is the acceleration due The conventional rectangular-notch, sharp-crested weir equation is considered in the form: pffiffiffiffiffi Q ¼ 2=3Cd 2g bh1:5 ð1Þ in which Q, the weir discharge; b, the weir width; h, the upstream head; g, gravitational acceleration and Cd, discharge coefficient. Show that the conditions for use of the fully contracted rectangular weir equation are met and calculate the water flow rate for the 0. Francis obtained the coefficient of discharge from the same general set of experiments as those stated for the contracted rectangular weir. RESUME L'étude propose un développement théorique afin de déterminer la relation qui régit le Feb 1, 2014 · For each configuration the data set were analyzed in order to find the discharge coefficient using equation, derived for the combined flow over the weir and from the bottom rectangular opening. It is considerably more complex than the USBR standard weir equations. 5 Mar 1, 2021 · The derivation of these relationships from the Bernoulli equation Flow over the sharp-crested weir is similar to the rectangular weir. 1, the well-known discharge formula derived from energy considerations [2] can be written as: (1) Q = C d 2 3 2 g b h 3 / 2 where Q is the discharge, b is the weir width, h is the head over the weir, g is gravitational acceleration and C d is named as the discharge coefficient assumed to represent all dimensional only, where a weir extends the whole width of the (rectangular) channel. Where: Q = discharge over weir, cfs (cms) L = length of the weir crest, ft (m) H = distance between water surface and the crest, ft (m) The suppressed rectangular, sharp-crested weir, shown in Figure 2 (a), has the weir length equal to the width of the channel. For the rectangular and Cipolletti weirs, the head To provide a single reliable, accurate method to model all rectangular weirs (suppressed, partially contracted, and fully contracted), the Kindsvater-Carter equation (Kindsvater and Carter, 1959) was developed. The flow springs clear of the weir at C, which is where we place the co-ordinate Dec 20, 2019 · The discharge coefficient accounts for the assumptions in the derivation and must be determined empirically for particular weir geometries. RESUME L'étude porte sur le déversoir à échan crure triangulaire à p laque mince comme app areil The “0” subscript indicates modular limit conditions. 5 Sharp-crested weirs are regularly used as frontal or lateral weirs Jan 1, 2018 · Commonly, the discharge over a sharp-crested weir (Q) under free-flow conditions in an open channel is expressed in terms of the following well-known equation (Henderson, 1966): (1) Q = 2 3 C d b (2 g) 0. All other weirs are classified as "weirs not sharp crested". As one of the most important and influential factors of discharge capacity, side slope can improve the hydraulic characteristics of weirs at special conditions. Basic definition sketch of the rectangular and trapezoidal weir (after Bos, 1976) The effective coefficient of discharge (C e ), is a function of relative depth ( ℎí µí±¢ í µí± ) and The discharge equation for a rectangular weir (a weir that spans a rectangular flume) is given as Q = K 2 g L H 3/2 In Eq. L = the length of weir in ft h 1 = head on the weir in ft. PU is the upstream weir height, PD the downstream weir height and b the weir width. [19] conducted laboratory research on rectangular sharp-crested side weirs and introduced a discharge coefficient equation for rectangular side weirs as a function of the ratio of the side weir's crest height to the flow depth upstream of the weir, the ratio of weir length to the main channel width, the ratio of weir length to List of Symbols A Cd D Cross-sectional area of flow ðm2 Þ Discharge coefficient of side weir ð − Þ Channel diameter ðmÞ g L p Q Q0 Qw q S t Ui, j u* w X, Y, Z y1 y+ Z1 Z2 δi, j ν νt ρ Specific energy in the main channel ðmÞ Fluid volume fraction in a cell ð − Þ Froude number at beginning of side weir on axis of main channel ð Mar 1, 2022 · More than three decades later, an experimental study of the variation in the discharge coefficient of triangular broad crested weir with different geometries located on a straight, rectangular main channel was conducted by Hoseini [19]. 16. 089, while the Cd values for the triangular weir ranged ACE2012 2 Figure 1. The experimental nappe profiles were mathematically modeled and combined with elements of free-vortex theory to derive a predictive equation for the weir discharge coefficient. Oct 18, 2015 · Two empirical equations were obtained to estimate the value of discharge coefficient in terms of effective head to crest height ratio, and upstream slope face of weir with high correlation Jun 1, 2021 · Keywords: V-notch, weir, discharge coefficient, weir height, approach velocity. to maintain the streamlines straight and parallel, the length of the weir is designed such that 0. 62. the weir (using one opening (which maybe already exist and may be only widened 75 expression to derive the discharge coefficient of flow passing over a rectangular sharp-76 crested weir. 4). Note that the orientation of the gate specified for reverse flow combinations is relative to the crest, not the flow direction, e. Apr 1, 2011 · For a rectangular weir as given in Fig. M. Theory: 1. Introduction . However, the coefficient does not remain constant for a ratio of head-to-crest length greater than one-third, and the actual discharge exceeds that given by the equation. The conventional weir equation is written in the form: (1) in which Q = the weir discharge; b = the weir length; h = the head on the crest; g = gravitational acceleration; and Cd = discharge coefficient. 1, the well-known discharge formula derived from energy considerations [2] can be written as: Q = C d 2 3 2 g b h 3 / 2 where Q is the discharge, b is the weir width, h is the head over the weir, g is gravitational acceleration and C d is named as the discharge coefficient assumed to represent all effects Rectangular Contracted Weir. 85. When the crest is "broad", the streamlines become parallel to the crest invert and the pressure distribution above the crest Jan 1, 2013 · Some of the resources that were used for data derivation are given as follows. Install the suppressed rectangular weir in the channel. The equations and conditions are the same as for the forward flow combinations (described above) but with reverse flow (Q<0). 5 ft. 82 l s−1 ). 2*h 0)*h 0 1. RECTANGULAR WEIRS Full width weirs: A weir which extends across the full width of the rectangular approach channel (B/b=1. This calculates the water flow rate over a rectangular contracted weir. 45 (where H is the water depth over the weir crest and L is the weir length) a porous weir acts similar to a solid weir and the effect of porosity (n) nearly vanishes. The head should be no less than 0. Three Models are used, each with different weir width to flume width DISCHARGE OVER A RECTANGULAR NOTCH OR WEIR | rectangular notch Apr 22, 2012 · A narrow crested weir is hydraulically similar to an ordinary weir or to a rectangular weir. The conclusion states that the actual discharge is measured by the discharge coefficient but the The rectangular weir (notch) is one of common devices used to regulate and measure discharge in irrigation projects. Analyzing the experimental data showed that the ratio of head over weir crest to weir height (h/P) can be applied to obtain a correction coefficient (k) for estimation of the discharge coefficient (C d). The rectangular-notch weir is illustrated in Figure 3 . Apr 23, 2021 · (GEP) model have been used to estim ate the coefficient of discharg e for rectangular side weir. 3. Here we are going to derive an expression for discharge (Flow r The flow capacity through a rectangular weir is given by the following formula, which applies to sharp edged rectangular weirs : Q=0. • The variation of C d with the upstream Froude num ber shows that C d decreases with t he Mar 1, 2021 · For H/L>0. The weir plate is smooth, plane, and perpendicular to the sides as well as the bottom of the approach channel. It is base Jul 11, 2016 · The weir coefficient, since it is a function of the gravitational constant, is not dimensionless and therefore has different values depending on which unit system you are using. It includes an introduction describing the objective, equipment, and theory. 05 P H Based on experimental work by Kindsvater (10), this is valid up to an HIP value of about 10. Full-width sharp-edged broad-crested rectangular weir in a horizontal channel of rectangular cross-section (ISO 3846, 2008) is considered. Discharge Over a Rectangular Notch or Weir The expression for discharge over a rectangular notch or weir is the same. 367 (in English units), and it does not depend on L or P like it does for a rectangular weir. The flow is caused by gravitational acceleration g and is characterised by total head over the weir H in the U profile (Fig Dec 13, 2018 · As the slope of upstream face of the rectangular broad crested weir is decreasing from 90 to 23 the weir discharge efficiency is increasing and reaching to its maximum through a parabola function Sharp crested weirs are widely used as discharge measuring device in laboratories, industries and irrigation channels. The main objective of this research was to investigate weirs with different openings numbers, diameters and locations to conclude the best decision for increasing the discharge D. Measure the length ‘L’ of the weir plate. Aug 13, 2009 · Moreover, using free-vortex theory, an equation was determined for the discharge coefficient of the rectangular sharp-crested weir. 1) the discharge, Q, may be written in terms of the measured head over the weir, h, the weir width, b and the discharge coefficient, C d [6]: (1) Q = 2 3 C d 2 g b h 3 / 2 where g is the gravitational acceleration. Statement B: In the case of a triangular weir with known values of the angle of weir and co-efficient of discharge, the height of water over the weir is the only data required for the computation of discharge. qghhvfslavohtqvmwivuvxanmjkhiqcmuhxfocgbiokoplomypyljprgbb