Pipe Roughness Research Articles

Relationship between shear strength and surface roughness of double-layered pipes by cold drawing

Abstract. Pipes applied to marine plants are used in deep-sea environments; therefore, they must be resistant to high pressure and corrosion. Because it is difficult to satisfy both of these factors in a single pipe, studies on a double-layered pipe are continuously being performed. An outer pipe should be made of carbon steel, with high pressure resistance, and an inner pipe should be made of stainless steel, with high corrosion resistance. A pipe formed by combining these two pipes is called a lined pipe. The shear strength of the lined pipe is an important factor because pipe cracking can occur due to stress concentration when two pipes are separated by bending or high pressure. Therefore, various processes have been applied to increase the shear strength. In this paper, we investigate the effect of the surface roughness of the bonding interface on the shear strength. Surface roughness is in units of micrometers, and it cannot be used for finite element method (FEM) analysis. Therefore, surface roughness should be converted into a friction coefficient to perform FEM analysis. The effect of surface roughness on shear strength was studied in the relationship between the results of pressure from FEM analysis and the shear strength test.

Closure to “Efficient Technique for Pipe Roughness Calibration and Sensor Placement for Water Distribution Systems” by Richárd Wéber and Csaba Hős

Closure to “Efficient Technique for Pipe Roughness Calibration and Sensor Placement for Water Distribution Systems” by Richárd Wéber and Csaba Hős

Discussion of “Efficient Technique for Pipe Roughness Calibration and Sensor Placement for Water Distribution Systems” by Richárd Wéber and Csaba Hős

Discussion of “Efficient Technique for Pipe Roughness Calibration and Sensor Placement for Water Distribution Systems” by Richárd Wéber and Csaba Hős

Investigation into the Effect of Cutting Conditions in Turning on the Surface Properties of Filament Winding GFRP Pipe Rings

There are numerous engineering applications where Glass Fiber Reinforced Polymer (GFRP) composite tubes are utilized, such as desalination plants, power transmission systems, and paper mill, as well as marine, industries. Some type of machining is required for those various applications either for joining or fitting procedures. Machining of GFRP has certain difficulties that may damage the tube itself because of fiber delamination and pull out, as well as matrix deboning. Additionally, short machining tool life may be encountered while the formation of powder like chips maybe relatively hazardous. The present paper investigates the effect of process parameters for surface roughness of glass fiber-reinforced polymer composite pipes manufactured using the filament winding process. Experiments were conducted based on the high-speed turning Computer Numerical Control (CNC) machine using Poly-Crystalline Diamond (PCD) tool. The process parameters considered were cutting speed, feed, and depth of cut. Mathematical models for the surface roughness were developed based on the experimental results, and Analysis of Variance (ANOVA) has been performed with a confidence level of 95% for validation of the models.

Optimal architecture for artificial neural networks as pressure estimator

ABSTRACT The knowledge of hydraulic parameters in water distribution networks can indicate problems in real time, such as pipe bursts, small leakages, increase in pipe roughness and illegal connections. However, an accurate indication relies on the quantity and quality of the data acquired, i.e., the number of sensors used to monitor the network and their location. It is not economic feasible have a great number of sensors, thus, the use of artificial intelligence, such as Artificial Neural Networks (ANNs) can reduce the lack of information necessary to identify problems, estimating hydraulic parameter through the few information collected. The reliability of ANNs depends on its architecture, so, in this paper, different conditions are tested for ANN training to identify which are the most relevant parameters to be adjusted when the ANN is used for pressure estimation.

Calculation of Hydrodynamic Characteristics of Apparatus with Regular Tubular Packing

Among the apparatuses with a regular arrangement of packing elements creating an in-phase mode of vortex interaction, which ensures high efficiency of the processes, it is interesting to use a standard tubular packing. Such packing allows additional advantages associated with heat supply or extraction directly in the contact zone of the interacting phases, which is very important for conducting some chemisorption processes. The research covers such hydrodynamic regularities as hydraulic resistance during a heat carrier movement in pipes and during external flow around a tubular beam, retained liquid amount and gas content of layer in the external flow around the tubular beam with liquid and gas flows. The research was carried out using an experimental setup with a heat and mass transfer apparatus with regular tubular packing. The medium used during experiments is water-air. The research methodology included standard methods for determining hydraulic resistance and retained liquid amount and visual observation and photographing of gas-liquid flows. The novelty of the research was equations – one for calculating the hydraulic resistance in pipes, taking into account local resistances and pipe roughness. The other ones for determining the pressure losses during the external flow around the tubular beam, the retained liquid amount, and the gas content of the layer, taking into account the vortex interaction of gas and liquid flows. Graphical and calculated dependences of the investigated hydrodynamic characteristics were obtained as a result of the conducted research of the hydraulic resistance during the heat carrier movement in the pipes, as well as the hydraulic resistance and the retained liquid amount during the external flow around the tubular beam with a change in the gas velocity and irrigation density. When the heat carrier flows in the pipes, the numerical values of the hydraulic resistance in the transient mode do not exceed 1.5 kPa, in the developed turbulence mode in the range of the Reynolds number from 1·104 to 6·104 DР varies from 1.5 to 53 kPa. With the external flow around the tubular beam, in the developed turbulence mode wg = 4 m/s and L = 25 m3/m2h, the hydraulic resistance is 85 Pa, the retained liquid amount is 4.5·10-3 m. The change in the irrigation density in this mode (developed turbulence) in the L range from 10 to 100 m3/m2h leads to an increase in the hydraulic resistance from 65 to 160 Pa, the retained liquid amount from 2.16·10-3 to 13.6·10-3 m. The calculated dependencies are the basis of the method for calculating the hydrodynamic characteristics of the apparatus with the regular tubular packing, which can be used to calculate industrial devices.

Effect of the surface of the rough pipe on the fluid flow rate

The concept of controlling the flow over the circular cylinder to reduce drag force and vibration caused by vortex flow has been explored by many researchers. One of them is by adding plates and helical strakes. However, the splitter plate is only useful for determining the direction of the current, while helical strakes increase drag force compared to cylinder forces of the same diameter. The problem that arises is that the surface roughness of the pipe will affect the characteristics of the fluid flow through it, so this study aims to analyze the characteristics and effects of fluid flow through the rough surface of the outer wall of the pipe by visualizing using Particle Image Velocity (PIV). The variation of pipe roughness used in this study is the roughness of sandpaper 100 and sandpaper 400 that encloses the pipe. The results showed that the addition of surface roughness resulted in the addition of the distance of the formation of vortex where the distance of 0.07 m was the longest distance from the bottom vortex formation on the pipe wrapped in sandpaper 100.

Assessment of optimal water distribution systems design under steady-state and transient conditions due to pipe roughness uncertainty

This paper presents a methodology to find the optimal design or rehabilitation of water distribution system (WDS) under both steady-state and transient conditions. Then, assessing the obtained optimal solution and studying its stability, reliability, due to uncertainty in pipe roughness coefficients (CHW). The WDS optimization objective is to minimize the rehabilitation cost by installing new pipes parallel to the existing ones achieving all hydraulic constraints. For this purpose, particle swarm optimization (PSO) is used as an optimization tool and Monte Carlo simulation (MCS) is applied to generate multiple realizations of CHW for different coefficient of variation (COVCHW). A comparison between crisp shape and continuous shape (S-shape) fuzzy membership functions is carried out to study the hydraulic availability indices to nodal pressure head values resulted from pipe roughness uncertainty. Both steady-state nodal and system reliabilities are estimated while, only the transient system reliability is calculated for the obtained optimal solution. The proposed methodology is applied on the New York City tunnel network (NYCTN) and the corresponding reliability is analyzed. Results show that as pipe roughness uncertainty increases, WDS reliability decreases.

Soft computing method for predicting pressure drop reduction in crude oil pipelines based on machine learning methods

In the oil industry, the drag-reducing agent has been used to reduce turbulent friction of fluids. The main effort of this study is to examine the feasibility of four novel machine learning models, namely multilayer perceptron, M5Rules, decision table (DT), and trees M5P to estimate the percentage of drag reduction. Then, the mentioned methods are utilized to identify a relationship between the input and output parameters of the crude oil pipeline system. The parameter percentage of drag reduction was taken as the essential output. In contrast, the input parameters selected the flow rate of oil, polymer concentration, kind of polymer, temperature, as well as pipe diameter and roughness. The predicted results obtained by the tools mentioned above were evaluated according to several known statistical indices, namely coefficient of determination (R2), mean absolute error (MAE), root mean squared error (RMSE), relative absolute error (RAE), and root relative squared error (RRSE) as well as novel ranking systems of color intensity rating and total ranking method. The training and testing results of the DT learning method for the R2, MAE, RMSE, RAE, and RRSE were (0.9616, 3.9008, 5.8698, 24.5259%, and 27.4406%) and (0.8964, 6.937, 10.318, 43.3841%, and 45.6581%), respectively. The obtained results, in analyzing the training and testing datasets, proved that DT is the best predictive network to predict the percentage of drag reduction.

Effects of production, PVT and pipe roughness on multiphase flow correlations in gas wells

The importance of gas production has increased as gas represents a clean source of energy. We studied different multiphase flow correlations for gas wells. We collected large database for bottomhole flowing pressure for different flow conditions and well configurations. In total, 32 gas wells were selected and our target was to study the effect of multiphase flow correlations input parameters on the accuracy of the predicted pressure drop. Several important multiphase correlations input parameters were selected for this study. These include condensate to gas ratio (CGR) and water to gas ratio (WGR) which represent the production conditions, API and specific gravity of surface gas (Ɣg) which represent PVT properties and the tubing roughness (ε) which represents the tubing condition. Our method was based on changing the values of these selected parameters by a percentage from its original value and determining the new predicted bottomhole flowing pressure. Consequently, we determined the new error compared to the actual measured bottomhole pressure. We performed 352 cases, and we could obtain the effect of the different parameters on both pressure drop calculations and the selection of the best correlation. Guidelines were developed to explain which parameters are more important to be measured accurately for different conditions.

Analysis of Rainwater Pipelines for Local Flooding Mitigation

PCSWMM was used to perform hydrodynamic simulation. Effect of water level, slope and diameter of rainwater pipelines on local flooding was investigated at free discharge and submerged discharge respectively. Bernoulli equation was applied to theoretical analysis. Results showed that increase of pipe slope and diameter could improve drainage capacity of rainwater pipes at free discharge. Rising water level seriously restricted drainage capacity of rainwater pipes. However, at submerged discharge, pipe slope promoted the construction cost, but it had no effect on its drainage capacity. With the increase of diameter, drainage capacity of rainwater pipes increased. Main factors on drainage capacity of pipes were water head different between upstream and downstream, pipe diameter and roughness coefficient. Hence, it’s recommended that urban drainage system should properly control water level and increase pipe diameter at submerged discharge. The results are important implications for rainwater pipeline design to prevent local flooding.

A new friction factor formula for single phase liquid flow through geothermal pipelines

Proper selection of pumps has been an important issue for energy efficiency in geothermal energy. In a research conducted among machines that consume electricity, pumps come first with 25 %. Accurate estimation of pressure losses is a key point in order to select pump systems. Hot water from the geothermal area is carried by pipeline systems. In this study, extensive experimental study is conducted at Izmir Katip Celebi University Flow Loop using pure water for fluid temperature from 25 °C to 60 °C, for four various relative roughness values, and for Reynolds Number ranges from 6.2 × 104 to 7.8 × 105. This study has mainly two objectives: First is to identify if the absolute pipe roughness values of commercially available pipes vary according to the pipe diameter. The second objective is to investigate fluid temperature effects on frictional pressure losses in rough pipes and to present a new friction factor correlation for using in geothermal pipelines, considering the fluid temperature effects. Experimental study shows that absolute pipe roughness varies substantially for pipe diameters. The proposed friction factor has a good agreement with explicit formulas of Blasius (1913) and Taler (2016) equations for smooth pipes and Colebrook (1939) equation for rough pipes, as well as experimental data at various temperature values.Additionally, frictional pressure losses are accurately estimated using new friction factor equation. Results show that both relative roughness and temperature have a significant influence on the friction factor for turbulent flow through rough pipes. For this reason, pipe roughness should be determined correctly and the effects of fluid temperature on pressure losses should be considered. This may influence frictional head losses per unit length and, consequently, the predicted pumping requirements in geothermal pipelines.

Fuzzy node flow analysis of water distribution networks using Jaya algorithm

Fuzzy analysis helps in understanding how the uncertainty in various independent parameters of water distribution network such as, nodal demands, pipe roughness values, reservoir heads, pipe diameters and so forth will affect the dependent parameters such as pipe velocities, discharges and nodal pressures. The membership functions of dependent parameters are obtained by considering membership functions of uncertain independent parameters. The Impact Table method from literature suggests a repetitive analysis by considering the monotonous relationship between dependent and independent parameters. The Impact Table method was also employed for carrying out fuzzy analysis under pressure deficient condition to obtain fuzzy membership function of nodal outflows. Optimization based methods of fuzzy analysis are more useful when relationship between dependent and independent parameters are non-monotonous. A novel algorithm, Jaya is used in this study for performing fuzzy analysis on a benchmark network by pressure dependent approach. The analysis is performed by setting up hydraulic model in the software EPANET and linking it with the MATLAB for performing optimization through an EPANET-MATLAB toolkit. The propagation of the uncertainties of the input parameters for some non-linear hydraulic responses were identified and the algorithm was found to be a powerful tool for optimization.

Calibration Procedure for Water Distribution Systems: Comparison among Hydraulic Models

Proper hydraulic simulation models, which are fundamental to analyse a water distribution system, require a calibration procedure. This paper proposes a multi-objective procedure to calibrate water demands and pipe roughness distribution in the context of an ill-posed problem, where the number of measurements is smaller than the number of variables. The proposed methodology consists of a two-steps procedure based on a genetic algorithm. Firstly, several runs of the calibrator are performed and the corresponding pressure and flow-rates values are averaged to overcome the non-uniqueness of the solutions problem. Secondly, the final calibrated model is achieved using the calibrator with the average values of the previous step as the reference condition. Therefore, the procedure enables to obtain physically based hydraulic parameters. Moreover, several hydraulic models are investigated to assess their performance on this optimisation procedure. The considered models are based either on concentrated at nodes or distributed along pipes demands approach, but also either on demand driven or pressure driven approach. Results show the reliability of the final calibrated model in the context of the ill-posed problem. Moreover, it is observed the overall better performance of the pressure driven approach with distributed demand in scarce pressure condition.

Simulation of Transmission of Drinking Water Sources to Reservoirs: Case Study PDAM Tirta Jati, Cirebon, Indonesia

Population dynamics have very important effects on ecosystems, including those related to water availability. The availability of clean water is closely related to the condition of the population in an area. Every human being must drink 8 (eight) glasses of water per day. Plants and animals also need water. So it can be said that water is one source of life. Regional Water Supply Company (PDAM) is a company whose ownership is held by the regional head as the operator of drinking water supply for the community. Companies are encouraged to utilize developing technology to manage their drinking water assets effectively and efficiently so they can improve services to the community. EPANET 2.0 is one tool that is suitable for connecting piping network models. Quantum Geographic Information System (QGIS) is a model simulating hydraulics which parameters can be launched through a processing stage. The master network system model created in QGIS was included in EPANET 2.0 for rasterization. Then enter the required data such as pipe length, height of each node, water flow per tapping, pipe roughness coefficient, and peak hour factor. The results of the analysis in the form of pipe hydraulics, such as pipe speed and pressure from each node are used as a basis for network development plans. The ratio of the total population per family in Sumber District in 2018 is 6 people/head of the family. The population in the administrative area served by PDAM is 22,560 people. Domestic water needs can be calculated based on data on average water usage per month recorded at PDAM Tirta Jati, Cirebon Regency. The number of domestic customers was 2,446 in August 2019 with an average monthly water consumption of 15.02 m3/unit. Based on analysis using Epanet and QGIS, parameter data for pipe flow rates are 0.63 - 1.05 meters/second. While the result for water pressure in the pipe is 140.95 meters at node 274.

Challenges in calibration of water distribution network: a case study of Ramnagar Elevated Service Reservoir command area in Nagpur City, India

Abstract Calibration of a hydraulic model is a challenging task as it considers the involvement of a large number of uncertain parameters. There are some parameters like length and diameter of pipes, for which fairly accurate values can be obtained. As with all hydraulic models, water demands are one of the main parameters that cause the most uncertainty in the model outputs. The calibration of the water demands is usually not feasible, which is attributable to the limited quantity of available measurements in most real water networks. However, some parameters like nodal demands and pipe roughness coefficients are estimated close to the actual values. Various types of valves are used for flow control by throttling. Hence, their setting in the field is also an important input to the model. Having more precise data helps in reducing time and results in better calibration as presented in the case study of one hydraulic zone served from Ramnagar Elevated Service Reservoir (ESR) (Zone II) in Nagpur City, Maharashtra State, India. This paper aims at presenting the complexities and challenges involved in calibration of the study area. It further describes the entire process from collection of the required data to the calibration of the network.

CFD analysis of the performance of elbow-meter with high concentration coal ash slurries

Elbow meter is a simple flow measuring device and its characteristics for the flow of single-phase fluids are reasonably well understood and the functional dependence of elbow meter coefficient (Ck) on parameters like Reynolds Number, radius ratio, pipe roughness etc. Is well documented in literature. Elbow meters are also being used for solid liquid flow in many industries. The present study aims to establish the characteristics of an elbow meter for high concentration coal ash slurry pipelines using validated CFD. High concentration coal ash slurries are known to behave as homogeneous fluids exhibiting behavior as Bingham plastic fluids. The validated CFD methodology has been used to predict the values of Ck for the flow of Bingham plastic fluid and establish its dependence on radius ratio, Hedstrom Number and Bingham Reynolds Number. Further, for the flow of high concentration fly ash slurry flows, Ck for any given radius ratio is observed to be independent of Hedstrom Number (over the range investigated He ≤ 105). Further, in fully turbulent flows, beyond a critical Reynolds number (ReB ≥ 5.3 × 103), Ck remains constant and is dependent only on the radius ratio.

Wave reflection and transmission test with pipe wall roughness and without roughness on the perforated breakwater

Waves towards the shore that have a porous breakwater building will experience reflection and transmission, to determine the height of reflection and transmission wave is needed a study by the process of generating waves on the flume with a porous breakwater building, the effect of wave changes in its propagation requires an experiment in the laboratory. This study was aimed to determine the height ratio of reflection and transmission wave by using a model of pipe structure as a wave reducer by adding the friction plane of the roughness of the walls in the pipe. A method of laboratory experiment on the wave generation flume has several variations consisting of 3 periods (T; 1,0 seconds, T; 1,1 seconds, T; 1.2 seconds) and 3 water depth (d) are 15, 30 and 36 cm, stroke to regulate the flap motion that determines the wave height (H) as a wave generator that is 4, 5 and 6 by comparing the model that uses pipe wall roughness and without roughness. The result of testing indicates that the height of reflection wave (Hr) and transmission (Ht) is strongly influenced by the period (T). If the period increases, Hr and Ht significantly decrease, the height ratio of reflection wave using pipe wall roughness is greater than without roughness. However, it inversely proportional to the height of transmission wave (Ht) were a model using pipe roughness is more efficient to reduce Ht than a model without pipe roughness.

EFFICIENCY INDICATOR FOR ASSESSMENT OF WATER DISTRIBUTION NETWORKS CARRYING CAPACITY

A water distribution network s (WDN s) flow capacity decreases over time mainly because of the unplanned demand growth at its consumption points, increased water loss, and increased internal roughness caused by aging of pipes. In this context, this work presents a new performance indicator, the Carrying Capacity Indicator (ICC). It will enable utility managers to evaluate WDNs hydraulic and energy efficiency. The ICC was applied in a real case study: a sector of the Jo o Pessoa WDN, in Brazil. Considering only design criteria (in relation to nodal demands and pipe roughness), the ICC decreased from 203.5% in the first year of the network s operation to 70.6% in its 30th year of operation. Simulation results are provided to demonstrate that the proposed indicator can be successfully applied to a wider class of WDNs.

Identification of Heat Supply Network Pipeline Roughness Based on AIOX-GA

The scale of heating system is expanding day by day and the structure of pipeline network is becoming more and more complex. Therefore, it is urgent for heating enterprises to establish accurate hydraulic models of pipeline network to assist their operation and management. The pipe roughness of heating pipeline is critical to hydraulic models, but unfortunately it is however uncertain. Thus, it is necessary to obtain the resistance coefficient values of pipe roughness of heating pipeline. At present, the pipeline roughness is commonly estimated with optimization calculation based on collected measurement data of heating systems. The optimization problem is however multi-dimensional and complex to solve. In this work, an auxiliary individual oriented crossover genetic algorithm (AIOX-GA) is proposed to optimize the problem of estimating the resistance coefficient values of pipe roughness. AIOX-GA adopts a crossover framework and is an auxiliary individual-oriented scheme, which is helpful to solve multi-dimensional problems. The performance of the improved algorithm is evaluated with simulation experiments. The results show that the proposed algorithm can accurately estimate the pipeline roughness and effectively improve the identification accuracy.