Values Of Discharge Coefficient Research Articles

Submerged flow over various shapes of piano key weir

The weir, an essential element of dams utilized for floodwater management, plays a crucial role in human life. Over the years, nonlinear weirs have advanced into Piano Key Weirs (PKWs). These PKWs provide enhanced discharge efficiency, a reduced structural footprint, and heightened cost-effectiveness. PKWs possess a sophisticated structure defined by numerous geometric parameters. The impact of these parameters on the discharge capacity is of paramount significance. This study aims to experimentally investigate the hydraulic of submerged PKWs with different plan shapes, including triangular, trapezoidal, and rectangular, with apex width to cycle width ratio of (A/w) of 0, 0.25, and 0.5, and magnification ratio (B/w) of 1, 2, and 3, respectively. The results indicate that submergence depends on the shape and size of the PKW. Furthermore, the efficiency of the PKW increases as the ratio of approach flow head to weir height (Ho⁄P) decreases and B⁄w increases. The influence of the shape of the PKW on the performance of the weir is more pronounced at higher values of B/w. Additionally, the order of the highest discharge coefficient values follows a pattern from the trapezoidal to triangular and rectangular PKWs. Specifically, for B⁄w = 2, the trapezoidal PKW exhibits an approximate improvement of 6 and 15 % in the discharge efficiency compared to the triangular and rectangular PKWs, respectively. A new equation was developed to predict the discharge coefficient for different shapes of PKWs under various hydraulic conditions. Based on the experimental data, this study offers valuable insights into the hydraulic behavior and discharge coefficient of PKWs. This research significantly contributes to enhancing our understanding and optimizing the performance of submerged PKWs in water management systems.

Improving Hydraulic Performance of Drip Irrigation Emitters Through CFD Analysis

A drip irrigation system delicately nourishes plant roots by gently delivering water drop by drop, ensuring minimal water loss due to runoff or evaporation. This method allows soil particles ample time to absorb and retain the water, promoting optimal plant hydration. To enhance the efficiency of drip irrigation, a mesmerizingly detailed 3D solid model of a drip emitter was meticulously crafted using cutting-edge SolidWorks software, revolutionizing the irrigation system's performance. CFD simulation technique is used to understanding the internal flow behavior and optimum pressure inside the in -line drip irrigation emitters. Their labyrinth structures of channels are main cause of change in flow behavior and optimum pressure in the drip irrigation emitters. Standard k-ɛ model and Enhanced wall function are used to simulate the flow behavior in labyrinth channels. Key findings are the efficiency of triangular channel is greater than the other channels (rectangular, trapezoidal and circular) based on analysis of flow rate. The value of Discharge coefficient of these channels from CFD simulation present a relationship of kCircular>kTrapezoidal>kRectangular>kTriangular. When the channel shape is smooth (like a circular channel) than the higher value of k. The efficiency of triangular channel is greater than the other channels (rectangular, trapezoidal and circular) based on analysis of flow rate. Discharge is increased by 76%, 68.42%,66.67% and 39.39% for circular channel, Trapezoidal channel, rectangular channel and Triangular Channel respectively for pressure range of 1.02m of water head to 10.2m of water head.

Analysis of discharge characteristics of a symmetrical stepped labyrinth side weir based on global sensitivity

Abstract In this paper, the discharge coefficient prediction model for this structure in a subcritical flow regime is first established by extreme learning machine (ELM) and Bayesian network, and the model's performance is analyzed and verified in detail. In addition, the global sensitivity analysis method is introduced to the optimal prediction model to analyze the sensitivity for the dimensionless parameters affecting the discharge coefficient. The results show that the Bayesian extreme learning machine (BELM) can effectively predict the discharge coefficients of the symmetric stepped labyrinth side weir. The range of 95% confidence interval [−0.055,0.040] is also significantly smaller than that of the ELM ([−0.089,0.076]) and the Kernel extreme learning machine (KELM) ([−0.091,0.081]) at the testing stage. The dimensionless parameter ratio of upstream water depth of stepped labyrinth side weir p/y1 has the greatest effect on the discharge coefficient Cd, accounting for 55.57 and 54.17% under single action and other parameter interactions, respectively. Dimensionless step number bs/L has little effect on Cd, which can be ignored. Meanwhile, when the number of steps is less (N = 4) and the internal head angle is smaller (θ = 45°), a larger discharge coefficient value can be obtained.

Utjecaj oblika krune na koeficijent prelijevanja linearnih preljeva

A detailed experimental laboratory analysis of the effect of crest shape on the discharge coefficient of sharp-crested weirs is presented in the paper. The experiments were conducted for four different crest shapes. The experiments and analyses show that discharge capacity, and discharge coefficient in particular, are significantly affected by weir crest height. It is stated in conclusion that rounded crest shape has the highest discharge capacity. In practice, sharp crested weirs are generally preferred to other crest shapes due to construction facility, although the discharge coefficient values of sharp crested weirs are lower compared to rounded crest shape.

Towards high-efficiency of hydrogen purification in metal hydride

Recent advancement on hydrogen (H2) retrieval in a mixture gas of H2/CO2 based on the metal hydride (MH) technique has attracted numerous interests. In this work, we implement the lumped element model simulation to conduct a theoretical approach on the hydrogen purification process. The influence of orifice geometry and temperature of the tank, and inflow gas rate (fin) is investigated. The results show that the discharge coefficient (DC) is affected by the tank's orifice geometry. The orifice shape is increasing the value of DC, as a result, the CO2 (impurity) outflow rate heightens during the venting process and thereby promoting to obtain a high hydrogen purity. By overcoming the exothermic/endothermic effect in the absorption/desorption step and a proper fin selection, we find an improvement in the hydrogen storage capacity (wt%) into MH and consequently the hydrogen recovery rate increases. A sharp improvement in orifice geometry and thermal conditions of the tank, and fin enhances the main targeted results (hydrogen purity and recovery rate) and ensures the proper operation of the MH technique.

Experimental Determination of the Flow Coefficient for a Constrictor Nozzle with a Critical Outflow of Gas

Reduction of energy expenditures required for various technological processes is a pressing issue in today’s economy. One of the ways to solve this issue in regard to liquefied natural gas (LNG) storage is the recovery of its vapours from LNG tanks using an ejector system. In that respect, studies on the outflow of the real gas through the nozzle, the main element of the ejector, and identifying differences from the ideal gas outflow, are of high relevance. Particularly, this concerns the determination of the discharge coefficient µ as the ratio of the actual flowrate to the ideal one, taking into account the energy losses at gas outflow through the nozzle. The discharge coefficient values determined to date for various nozzle geometries are, as a rule, evaluated empirically and contradictory in some cases. The authors suggest determining the discharge coefficient by means of an experiment. This paper includes µ values determined using this method for the critical outflow of air to atmosphere through constrictor nozzles with different outlet diameters (0.003 m; 0.004 m; 0.005 m) in the pressure range at the nozzle inlet of 0.5–0.9 MPa. The obtained results may be used for the design of an ejector system for the recovery of the boil-off gas from LNG tanks, as well as in other fields of industry, for the design of technical and experimental devices with nozzles for various applications.

Effects of Upstream Flow Disturbances on Elbow Meter Performance

In order to fill gaps in research into the use of elbow flow meters and to reconcile both a lack of published standards and differing recommendations on the necessary minimum lengths of straight pipe that should be installed upstream of an elbow flow meter to ensure sufficiently accurate flow measurement, physical data were collected on 50 mm nominal (52.5 mm or 2.067 inch actual), 150 mm nominal (154.05 mm or 6.065 inch actual), and 305 mm nominal (304.8 mm or 12.00 inch actual) long-radius elbow meters to determine discharge coefficients in a straight-line pipeline configuration. The 150 mm (6-inch) long-radius elbow meter was further tested in order to determine the effects of different upstream disturbances on the accuracy of its metering performance. Three different upstream disturbances were tested at upstream distances of 25, 10, and 5 diameter-lengths, including: a single elbow in-plane “S” orientation, a single elbow in-plane “U” orientation, and a double elbows out-of-plane orientation. Discharge coefficients were calculated for each configuration at the three variable upstream distances between the upstream flow disturbance and the meter and compared to the straight-line calibration values to identify the percent difference shifts in the average discharge coefficients. Most importantly, findings from the present study conclude that the discharge coefficients for all elbow meter installations stabilize for pipe Reynolds numbers greater than 300,000. Additionally, even at upstream distances of 25 pipe diameter lengths (3.81 m or 12.5 feet) each of the three upstream flow disturbances continued to exhibit effects on the calculated discharge coefficients for the elbow meter; the observed difference in the average discharge coefficient for the two single elbow in-plane configurations “S” and “U” were within 1.00% of the straight-line values. Finally, the double elbows out-of-plane discharge coefficient values remained constant, regardless of the three tested distances between 5 and 25 diameter lengths between the elbow meter and the upstream flow disturbance, showing a more predictable shift in discharge coefficient than the two single elbow in-plane configurations.

Experimental study on the discharge coefficient of perforation behaviors during hydraulic fracturing treatments

The discharge coefficient (Cd) affects the perforation pressure drop during the hydraulic fracturing treatments. Given the changes in completion procedures, especially with horizontal wells, this absence of research on the Cd value indicates that many times over-simplification of the term is applied in practice. The research outlined in this paper focuses solely on the Cd term and the various conditions that are encountered downhole and the resulting impacts on perforation friction. This research provides an understanding into the influence of various factors on the discharge coefficient. Perforation hole size, perforation plate thickness, perforation hole geometry, downstream restrictions, friction reducer, fluid viscosity and horizontal behaviors are investigated in this work. In this study, a low pressure setup was built to investigate the effect of the previous factors on the discharge coefficient and subsequently the pressure loss through the perforations in hydraulic fracturing treatments. The experimental results show that the perforation hole size does not impact the discharge coefficient. However, perforation plate thickness, friction reducer fluid loading and fluid viscosity has a positive relation with the discharge coefficient value. In other words, a clear increase in the Cd value was observed when these parameters were increased for all the conducted tests. For different perforation hole geometries, the results show that the smooth and tapered edge hole has a larger Cd value than the same shaped sharp-edge hole. When a downstream restriction is installed, the Cd value increases as the distance between the downstream reflection plate and the perforated plate increases. The results of the horizontal well behaviors show that the Cd value of the perforated horizontal casing is slightly higher than Cd value for the perforated plate. Overall, this study on the effect of influencing factors on the perforation Cd value can help form a better understanding of perforation pressure drop behaviors and modify the design of limited-entry techniques.

Investigation of discharge coefficient of louvre openings in naturally ventilated buildings

Louvre openings are widely used for ventilation in residences at tropical regions. Traditional households rely primarily on natural ventilation for cooling instead of using air conditioners throughout the year. Hence, a design strategy that maximizes the natural ventilation rate with an accurate discharge coefficient is necessary. The discharge coefficient for a traditional window without a louvre is 0.6. However, studies on discharge coefficients for louvre openings with sashes are lacking. Discharge coefficient will differ according to the installed sash owing to increased contraction and friction losses. Therefore, we determined the discharge coefficient value for various sash angles and the impact of the louvre geometric parameter on the discharge coefficient. To investigate the effects of geometry on the discharge coefficient, real-time natural ventilation rate was quantified using the tracer gas (constant concentration) method. Pressure difference, outdoor wind velocity, and temperature difference were also measured. The opening types were divided into three cases: louvres with a sash angle of 0°, 15°, and 30° with similar opening areas. The results show that discharge coefficients for louvres with sash angles of 0°, 15°, and 30° are 0.80, 0.62, and 0.41, respectively, indicating that the coefficient decreases with increasing sash opening angle.

Anti-phase oscillations of an elliptical cavitation vortex in Francis turbine draft tube

In this paper, the dynamic behavior of a precessing cavitation vortex featuring an elliptical cross section in Francis turbine draft tube is investigated. This phenomenon may occur for values of discharge coefficient within 70%–85% of the discharge coefficient at the best efficiency point, for which Francis turbines can experience the onset of the so-called upper-part load (UPL) instability. The latter is characterized by the propagation of high-amplitude synchronous pressure fluctuations through the complete hydraulic circuit. High-speed visualizations of the cavitation vortex are performed on a Francis turbine model by means of two cameras synchronized with pressure sensors arranged along the draft tube for different Thoma numbers at a given discharge coefficient. A simplified analytical model of the cavitation vortex is proposed. It enables the interpretation of the video post-processing results in the frequency domain and the estimation of both the vortex cross section dimensions and their oscillations with time. It is first demonstrated that both the vortex cross section ellipticity (given by the ratio between its semi-major and semi-minor axes) and the amplitude of its oscillations are directly correlated with the amplitude of UPL pressure fluctuations during intermittent UPL instability. Furthermore, the evolution along the draft tube of the dimensions of the elliptical vortex cross section and their oscillations during fully developed UPL instability is highlighted. The ellipticity of the vortex cross section increases as the vortex center position gets closer to the draft tube wall away from the turbine outlet. In addition, the vortex cross section dimensions oscillate with opposite phase from either side of a pressure node located along the draft tube. This results in low oscillations of the total void fraction in the draft tube, compared with results obtained locally. This effect should be considered in the one-dimensional modeling of the cavitation flow during UPL instability for further stability analysis. The new insights on UPL instability presented in this paper may potentially lead to a better theoretical understanding and modeling of this phenomenon in Francis turbines draft tube.

Outlier robust extreme learning machine to simulate discharge coefficient of side slots

As the first time, this paper attempts to recreate the discharge coefficient (DC) of side slots by another artificial intelligence procedure named "Outlier Robust Extreme Learning Machine (ORELM)". Accordingly, at first, the variables affecting the DC comprising the ratios of the flow depth to the side slot length (Ym/L), the side slot crest elevation to the side slot length (W/L), the main channel width to the side slot length (B/L), as well as the Froude number (Fr) are determined and subsequently five ORELM models (ORELM 1 to ORELM 5) are created utilizing these variables. From that point forward, laboratory measurements are arranged into two datasets comprising training (70%) and testing (30%). At the subsequent stage, the best model alongside the most affecting input variables is presented by executing a sensitivity examination. The most impressive model (i.e., ORELM 3) reproduces DC values as far as B/L, W/L and Fr. It is worth focusing on that ORELM 3 forecasts DC values with worthy precision. For instance, the correlation coefficient (R), the scatter index (SI) and the Nash–Sutcliffe effectiveness (NSC) for ORELM 3 are acquired in the examination state to be 0.936, 0.049 and 0.852, independently. Examining the outcomes yielded from the simulation demonstrates that W/L and Fr are the most impacting factors to reproduce the DC. Besides, the findings of the sensitivity examination uncover that ORELM 3 acts in an underestimated way. Finally, a computer code is put forward to compute the DC of side slots.

Improving the understanding of on-site stormwater detention performances

ABSTRACT On-site Stormwater Detention has been used around the world to reduce stormwater peak flow at lot scale. However, few studies have evaluated its performance as well as its hydrological and hydraulic parameters on a real scale. To evaluate these variables, two OSDs were monitored in Belo Horizonte/Brazil. Based on the analysis of monitoring data, it was observed that: (i) the OSDs average efficiencies in peak flow damping were higher than 50%; (ii) the storage volume per catchment area was close to 25 L/m2; (iii) the short tubes discharge coefficients were approximately 0.90 and; (iv) the shape of inflow hydrographs were similar to hyetographs. The use of the Unit Hydrograph Modified Rational Method properly represented the rain-runoff transformation. The findings could be used in OSD design to determine the inlet hydrograph, to pre-sizing the storage volume based on contribution area and to use the proper discharge coefficient value for outlet device.

Hydraulic Performance of Sharp-Crested Labyrinth Weir

Weirs are used as a control structure in the waterways. Among the influencing geometrical parameters on the weir performance is the total crest length. Experimental work on 27 geometric models of two-cycle Labyrinth shape crest weir is tested. The tested physical models consist of three weir heights, three apex widths and the sidewall angle is between (4.67°≤ α ≤ 19°), with three models of rectangular labyrinth weirs. The weirs of the wider apex and the same total length perform better and its coefficient of discharge is higher. Labyrinth weirs of longer sidewall length and contents same apex width performance batter. The larger value of sidewall angle and for a constant apex width reduces the value of discharge coefficient. The value of Cd range from (0.34-0.83) for the ratio of upstream head to the weir height (h/P) is ranged (0.08-0.48). The equations to predict the value of the discharge coefficient are suggested within the limitations of the present study.

ГИДРАВЛИЧЕСКИЙ РАСЧЕТ РЕЗЕРВНОГО ВОДОСБРОСА (ВОДОСЛИВА С ШИРОКИМ ПОРОГОМ)

Purpose: to carry out hydraulic studies and calculations of a reserve spillway structure (broad-crested weir) of a rockfill dam. Materials and methods. Current studies show that in open channels the regime of fluid movement can be different, and the boundary surfaces of the channel in some cases should be considered as hydraulically smooth, in others – as hydraulically rough. The broad-crested weir of rectangular and trapezoidal section is considered. To determine the experimental discharge coefficient of the reserve spillway of an earth rockfill dam, the known dependences for unflooded broad-crested obtained by A. R. Berezinsky and D. I. Kumin were used. Results. Based on the results of comparing the calculated flow coefficients with the experimental data of other authors, close values with the data of A. R. Berezinsky and D. N. Kumin were obtained. At the same time, the values of the discharge coefficients of the water discharge according to Berezinsky and Kumin are in the range of 0.339 and 0.324, which confirms their compliance and high accuracy. The results of the calculation of the filtration flow rate through the rockfill of the dam with a reserve spillway are the filtration flow rates in the range of 726.81–2260.76 m³/s. Conclusions. The performed calculations showed that the values of the discharge coefficients of the weir of a trapezoidal section correspond to the data obtained by A. R. Berezinsky and D. I. Kumin. At the same time, the values of the spillway discharge coefficients by Berezinsky and Kumin are within acceptable limits, which confirms their compliance. The average flow velocities passing through the broad-crested weir were: for profile 1 – 3.76 m/s, for profile 2 – 0.612 m/s, for profile 3 – 2.13 m/s.

Determination of Discharge Coefficient for both Semicircular and Triangular Labyrinth Weirs

A Labyrinth weir is a type of nonlinear weir folded in plan-view, with the ability to pass a large flow at low heads due to an increase in the effective length of the weir crest for a given channel width. The discharge coefficients (Cd) were experimentally determined for both semicircular and triangular labyrinth weirs of varying sidewall angles (α) under free-flow conditions using eight physical models. Dimensional analyses are conducted using the Buckingham π theorem to find the dependent and non-dependent variables. A nonlinear empirical equation was developed using (Statistical Package for the Social Sciences 22) software. The findings show that the discharge coefficient decreases with the increase of headwater to (Ht/P) for both types of labyrinth weir with different plan forms. It is found that the efficiency of the semicircular and triangular labyrinth is higher than linear weir for (Ht/P ≤ 0.45) and decreases with increasing the value of (Ht/P) due to interference of flow between the layers in downstream. The obtained results revealed that the discharge coefficient (Cd) values obtained empirically using multivariable power regression and 5th degree polynomial equations considerably agree with the experimental data, for both of the semicircular and triangular labyrinth weirs. Furthermore, the correlation coefficient R2was (0.9951) and (0.9637) using 5th degree polynomial equation, and their values were (0.9643) and (0.9274) using multivariable power regression equation for both semicircular and triangular labyrinth weir models, respectively. The results in the present study compared quite well with the predicted results of the proposed equations obtained by other investigators.

Computational fluid dynamics analysis of flammable refrigerant leakage through a microcrack

Hydrofluorocarbons(HFCs) are potent greenhouse gases in refrigeration systems, and their contribution will accelerate climate change. In the context of global warming, low global warming refrigerants have to be reconsidered, these refrigerants are commonly flammable, so systems that use them can pose a risk. Thus, an analysis of potential pipe leaks in refrigeration systems is urgently needed. In existing research on refrigerant leak, most studies have examined holes as leak points. However, the true morphology of leak points is commonly long and extremely narrow. Therefore, a round-pipe microcrack leak model with crack opening displacement (COD) ranging from 10 to 50 µm were built to perform a simulation and experiment. The Fluent (v.20, ANSYS Inc.) software performed computational fluid dynamics analysis. The R290, R32, and R1234yf refrigerants were simulated, and the orifice flow equation was introduced to calculate leakage from the microcrack. An axial and circumferential microcrack model was constructed, and the experiment validated the simulation with largest relative error of 2.9%. The simulation results indicated that for side flow through the microcrack, using the conventional discharge coefficient (Cd) in the orifice equation may be unsuitable. Accordingly, based on the simulation results, empirical equations for predicting the Cd of axial microcrack when R290, R32, and R1234yf are leaking are obtained. Additionally, the effect of length-to-diameter ratio and orifice-to-pipe-diameter ratio on Cd are also discussed. Compared with existing studies, a smaller infinity discharge coefficient value (Cd∞) was observed when COD < 30 µm.

FLUID FLOW STUDY IN VARIOUS SHAPES AND SIZES OF HORIZONTAL AXIS SEA CURRENT TURBINE

The ducted tidal turbine models have been developed to utilize the conversion of the kinetic energy on ocean currents. The research in refining the turbine characteristics has been carried out by modifying the turbine’s shape and size. This study investigated flow characteristics in the meridional section of five ducted turbines models for seawater flow with velocity U0 = 1.5 m/s. The ducted turbine design and construction have five different impeller house diameters and fixed inlet and outlet diameters. The potential energy flow theory and experimental data are used to analyze the flow characteristics of the model. The results show that flow velocity in the x-direction at the inlet and outlet cross-section is getting smaller, reducing the impeller house cross section. Each impeller house size reduction increases the flow speed in the impeller house cross-section and also pressure on all other cross-sections tested. In the inlet area, the increased pressure indicates a decrease in speed flow and discharge coefficient value. The discharge coefficient value decreases from CQ = 0.9 at the diameter ratio of dr = 1 to CQ = 0.56 at the diameter ratio of dr = 0.375. The maximum value of power coefficient was determined at dr = 0,61÷0.73 or dr = 0.69 which is equivalent to average internal flow velocity Vr =2.0÷2.6 m/s and the static pressure ps = 97.1÷ 94.4 kPa. At the ratio value of D0/D2 = 0.83, the optimal diameter ratio dropt=0,61÷0.73 is in line with the duct model of case 3 and case 4, but it may be determined solely as for case 4.

EXPERIMENTAL STUDY OF FLOW THROUGH TRAPEZOIDAL WEIR CONTROLLED UNDER A SEMI-CIRCULAR GATE

Different parameters of a weir model have a great effect on the discharge coefficient. In this experimental study the effect of varying angle of a trapezoidal weir coupled with a below semi-circular gate is determined. The result showed that the higher the value of the higher the coefficient of discharge. The respective average discharge coefficient of the block model and the trapezoidal weir models are; 0.48031,0.48880, 0.49565, 0.49647, 0.49892 and 0.49934. As such the trapezoidal weir with has the highest value of average discharge coefficient =0.49934. Hence the most efficient. Linear and nonlinear regression analysis were used to generate mathematical equations that can be used to predict the flow rate Q for the combined weir-gate structure and the discharge coefficient of the most efficient model with respectively. The discharge coefficient for the most efficient weir model was found to be 3.81% more than that of the block model (with rectangular weir). The predicted coefficient of discharge for the most efficient model was also found to be in good agreement with the observed discharge coefficient with a percentage error in the range of 0.4%

Effect of Different Channels on Discharge Coefficient of Labyrinth Weirs

In this study, the effect of channel-bed slope and non-prismatic converging channel on the discharge coefficient of labyrinth weirs is numerically investigated utilizing FLOW-3D model. Numerical simulation results show that modifying the labyrinth weir channel through both methods improves the discharge coefficient. Among the selected bed slopes and converging channel wall, the slope of β=4% and angle of θ=10° yielded the highest discharge coefficient. For a ratio HT/P=0.1, (HT: flow height, P: weir height) the discharge coefficient and discharge rate for bed slope and convergence angle case were 19.22%, 23.9% and 22.28%, 25.91% higher than for a conventional labyrinth weir in prismatic channel, respectively. Simultaneous application of a bed slope and convergence angle significantly increases the discharge coefficient and discharge value case were 28.64% and 30.42% higher than compared to the conventional case. Therefore, changing the bed slope and wall angle of the weir channel increases the discharge coefficient and in this type of weir and these design alterations should be considered in weir design.

Experimental Determination of the Discharge Coeffcient Through Circular Orifice in PVC Pipes

Abstract Real water losses derived from water supply systems represent an important topic, nowadays. It is difficult to predict and to calculate the water lost volume, these values being crucial in any water balance. In addition, the leakage flow can be estimated only when the geometric and hydraulic characteristics of the pipes and the period of time associated to the leakage are known. Also, by using the equation of the water flow can be obtained inaccurate values, especially when incorrect values of discharge coefficient are used. The values of the discharge coefficient can vary between 0.6 and 0.85, depending on a multiple aspects, such as the pipe diameter, the orifice size and shape, the pipe material, the orifice position on the pipe wall, the pipe thickness and the hydraulic parameters of the water (flow and pressure). This paper is focused of an experimental study of a leak simulation in a PVC pipe. Thereby, a circular orifice is drilled on PVC pipe wall and the influence of the water flow and pressure on the discharge coefficient (Cd) is analysed. The experimental values obtained for de Cd are 0.59 - 0.86, values that are in accordance with the results from similar studies.