Even though these losses are called minor, they can be. Such losses are generally termed minor losses, with the apparent implication being that the majority of the system loss is associated with the friction in the straight portions of the pipes, the major losses or local losses. Head loss in pipe flow system due to viscous effect i. Studies will be made on how to express losses caused by a change in the cross sectional area of a pipe, a pipe bend and a valve, in addition to the frictional loss of a pipe. Friction loss along a pipe introduction in hydraulic engineering practice, it is frequently necessary to estimate the head loss incurred by a fluid as it flows along a pipeline.
References for pipe head loss with worked examples. Associate professor, mechanical and materials engineering department portland state university, portland, oregon. The pressure losses across two sections of pipe, with inner diameters of 0. If the pipe is long enough the minor losses can usually be neglected as they are much smaller than the major losses. For laminar flows, which occur less frequently, the equation for the minor losses is k vavg mu d gamma. The energy loss is expressed in the general form, h l kv2 2g eq. In this practical you will investigate the impact of major and minor losses on water flow in pipes. Major head loss due to friction in pipes and ducts. To measure flow losses and pressure characteristics of different pipes and piping components. Apparatus the water pipeflow assembly is located along the east wall, in the model annex ma of the iowa institute of hydraulic research iihr and consists of. Minor losses local pump tee valve outlet elbow inlet pipe b vena contracta flow separation at corner separated flow separated flow q pipe entrance or exit sudden expansion or contraction bends, elbows, tees, and other fittings valves, open or partially closed gradual expansions or contractions.
Such losses are generally termed minor losses, although they often account for a major portion of the head loss. The minor loss coefficient can be expressed by rearranging 1 to. For flow in a circular pipe, an expression for the head loss due to skin friction can be developed by applying the principles of conservation of energy and linear momentum 1. This is different from major losses because those come from friction in pipes over long spans. Major and minor losses due to pipe diameter and fitting kade campbell abstract onger pipe with a smaller diameter and several types of fittings is bound to have high head losses and high frictional factors for many different volumetric flow rates. Minor loss coefficients for storm drain modeling with swmm. There are many types of losses of head for flowing liquids such as friction, inlet and outlet losses. Pdf evaluation of energy losses in pipes researchgate. Minor in comparison to friction losses which are considered major. Friction loss al ong a pipe introduction in hydraulic engineering practice, it is frequently necessary to estimate the head loss incurred by a fluid as it flows along a pipeline.
The major and minor losses in pipes is due to the friction in the pipes and the fitting type of each pipe and the connection. The resistance to flow in a pipe network causes loss in the pressure head along the flow. Minor losses at elbow or bend pipe losses in fittings such as elbow, valves etc have been found to be proportional to the velocity head of the fluid flowing. In the case of the minor losses, the observed head loss is due to the loss in the object itself plus pipe friction. Minor loss coefficients for storm drain modeling with swmm william h. Major and minor losses in pipes and fittings john w llorens abstract. You created this pdf from an application that is not licensed to print to. The pressure head lost due to flow through pipes and other losses.
In part 1 of this tutorial, a geometry and mesh like the one shown to the right will be created. Example lab report losses civl2310 fluid mechanics. The effects of these usually do not play a major role in the overall losses of the pipe system individually, but can still add up quickly together. Minor losses along with major losses are responsible for pressure drops along a. Major and minor losses in pipes mechanical engineering. Minor losses in pipes come from changes and components in a pipe. For the major losses, the volumetric flow rate was computed by using the equation. Pdf study of pressure losses in piping system researchgate.
This tutorial shows how to use inflation to generate a fine grid near a wall, how to generate an unstructured quad mesh everywhere else, and how to sweep the mesh along the pipe. M6 head losses major losses minor losses example problem total head loss friction loss extended bernoullis equation in the analysis of piping systems, pressure losses are commonly expressed in terms of the equivalent fluid column height called head losses h l. The volumetric flow rate is the velocity of the fluid multiplied by the crosssectional area. Minor pressure head loss in pipe and duct components. These losses are usually known as minor losses hlm. Pdf pipes made of plastic materials are generally used in pipelines and the laterals of irrigation systems.
Energy losses in pipe flow major energy loss due to friction minor energy losses a. Energy losses when a fluid is flowing through a pipe, the fluid experiences some resistance due to which some of the energy of the fluid is lost. The overall head loss across a pipe network consists of the following. If angle increases in pipe enlargement minor losses increase if angle decreases minor losses decrease, but you also need a longer pipe to make the transition that means more friction losses therefore there is a tradeoff. Minor losses here are some sample loss coefficients for various minor loss components. Bends, expansions, contractions, valves, fittings, and meters are a few of them.
Experimentally, two sections of pipe with diameters of 0. The specific hydraulic model that we are concerned with for this experiment is the energy losses. Pdf minor losses in pipes venkitaraj konery purushothaman. Fittings commonly used in the industry include bends, tees, elbows, unions, and of course, valves used to control flow. Losses due to the local disturbances of the flow in the conduits such as changes in cross section, projecting gaskets, elbows, valves and similar items are called minor losses. Minor losses in pipes losses caused by fittings, bends, valves, etc. Minor losses in pipes come from changes and components in a pipe system. The value of k is typically provided for various devices. Pipes in parallel are pipes with different diameters and same lengths, where each pipe is connected separately to increase the discharge. For horizontal pipe, with constant diameter this loss may be measured. The major and minor losses of pipes are computed for the technovate fluid circuit system and an edibon energy losses in bends module fme05. Minor loss coefficients for different bend angles and different bend radius of these pipes are ascertained, using both experimental method and numerical analysis. Losses are proportional to velocity of flow, geometry of device 2 h k v g 2 l.
Major and minor losses due to pipe diameter and fitting. Head loss in pipe flow major and minor losses portland state. Method for determining friction head loss along elastic pipes article pdf available in irrigation science 325. These additional components add to the overall head loss of the system.
Empirical data on viscous losses in straight sections of pipe are correlated by the dimensionless darcy friction factor f. Minor losses in pipe flow are a major part in calculating the flow, pressure, or energy reduction. It was concluded that the longer and more gradual turn in an elbow caused a lower minor loss coefficient k0. The minor loss coefficient can also be greater than 1 for some components. Major head losses are dependent on the friction factor, and the friction factor is. Minor head loss due to components as valves, fittings, bends and tees. Pdf method for determining friction head loss along elastic. In minor losses, the components such as valves and bends interrupt the flow of fluid and cause additional losses to the system due to flow separation and mixing. This classification into major and minor head losses is rather relative. There were no major changes in technical content and the original authorship was retainedthe editor of this edition was. Frost in the 1990s, as one of the updates to version 4.
The loss coefficient is found by the pressure loss divided by. To find the major losses throughout the system, a technovate fluid circuit system was used. Minor losses is a term used to describe losses that occur in fittings, expansions, contractions, and the like. Figure 5 shows the schematic layout of the pipe network to. Just as certain aspects of the system can increase the fluids energy. Friction head losses in straight pipes of different sizes can be investigated over a range of reynolds numbers from 103 to nearly 105, thereby covering the laminar. There are two types of head losses in pipe flow system i. In addition to energy or head loss due to friction, there are always head losses in pipes due to an enlargement or contraction of the flow section, bends, junctions, and valves etc. The minor losses are any head loss present in addition to the head loss for the same length of straight pipe.
So, minor loss are that which are very small as compared to the major loss, but and these losses occurs generally due to change in velocity, in the pipe, because of. Pdf pressure losses are very important factories that effects on the flow in piping. Minor loss coefficients were determined for a right angle bend, a small elbow, a medium elbow, a large elbow, a sudden contraction in pipe diameter from 40mm to 20mm, and a sudden enlargement in pipe diameter from 20mm to 40mm. For example, it may be desired to predict the rate of flow along a proposed pipe connecting two reservoirs at different levels. Minor losses in pipe flow are a major part in calculating the flow, pressure, or energy reduction in piping systems. In some cases, minor losses may be greater than major losses cengel and cimbala 2014. Entry length near the beginning of the pipe, the flow is not fully developed.
Major losses h major, and minor losses h minor i major losses major losses refer to the losses in pressure head of the flow due to friction effects. I was assigned there to analyze one pipe flow problem and to produce the outcome in front of the team leader and i had recalled the concept of head losses in pipe flow at that time to produce the required details. The objective of this experiment is to calculate loss coefficient k value and head loss. For the love of physics walter lewin may 16, 2011 duration. Materials and methods major losses to find the major losses throughout the system, a technovate fluid circuit system was used. You have been given the length between the two tapping points, the flow rate and the observed pressure difference which you convert to h l.
The objective of this experiment is to measure the effects that pipe diameter have on the friction factor, or major losses, and the effects that various fittings have on the minor losses in pipes. In other cases the minor losses are greater than the major losses. As can be seen, the head loss of piping system is divided into two main categories, major losses associated with energy loss per length of pipe, and minor losses associated with bends, fittings, valves, etc. In addition to head loss due to friction, there are always other head losses due to pipe expansions and contractions, bends, valves, and other pipe fittings. For more videos click on playlist link shown below v fluid mechanics and machinery fmm diplo. These minor losses cause nonuniformities in the flow path, resulting in small energy losses due to. Note that the larger velocity the velocity associated with the smaller pipe section is used by convention in the equation for minor head loss. Pdf method for determining friction head loss along. After completing my engineering, i had joined an organization and that organization was in chemical manufacturing business. Experiment image and source credits minor loss in pipe or duct components. Minor secondary head losses occur at any location in a pipe system where streamlines are not straight, such as at pipe junctions, bends, valves, contractions, expansions, and reservoir inlets and outlets.
Neglecting minor losses, it is obvious that the total head loss hl between the two tanks is the same as the friction losses through each pipe. Energy losses due to frictional effects of pipe or duct material or due to a change in velocity within a fitting cause energy loss in flowing fluids. When two or more pipes of different diameters or roughness are connected in such a way that the fluid follows a single flow path throughout the system, the system represents a series pipeline. Major head loss friction loss what is nuclear power. Liquid moving through pipes carries momentum and energy due to the forces acting upon it such as pressure and gravity. Method for determining friction head loss along elastic pipes. Due to the complexity of the piping system and the number of fittings that are used, the head loss coefficient k is empirically derived as a quick means of calculating the minor head losses. In a series pipeline the total energy loss is the sum of the individual minor losses and all pipe friction losses. The major loss is that due to frictional resistance of the pipe, which depends on the inside roughness of the pipe. In industry any pipe system contains different technological elements as bends, fittings, valves or heated channels.
The overall head loss for the pipe system consists of the head loss due to viscous effects in the straight pipes, termed the major loss and denoted hlmajor. Minor head loss head loss or pressure loss due to components as valves, bends, tees and the like in the pipe or duct system. The head loss in various pipe components, termed the minor loss and denoted hl minor. Like pipe friction, these losses are roughly proportional to the square of the flow rate. Friction and minor losses in pipelines 1 school of engineering science mechatronics systems engineering objective to measure flow losses and pressure characteristics of different pipes and piping components. Energy loss resulting from friction in a pipeline is commonly termed the friction head loss hf this is the head loss caused by pipe wall friction and the viscous dissipation in flowing water. Minor losses, on the other hand, are due to pipe fittings, changes in the flow direction, and changes in the flow area.
The minor losses were found by calculated the pressure drops across various pipe fittings on the edibon energy losses in bends module. These losses effect the volumetric flow rate of the fluid through the system. Friction losses in pipe fittings resistance coefficient k. Example lab report losses civl2310 fluid mechanics uon. Major head loss head loss or pressure loss due to friction in pipes and ducts. Major losses occur due to friction within a pipe, and minor losses occur at a change of section, valve, bend or other interruption. Friction and minor losses in pipelines 3 school of engineering science mechatronics systems engineering 1 return pipe with return valve to water tank 6 crosssection expansion pvc 2032 2 galvanized steel pipe, 12 7 section for interchangeable measuring objects 3 cu pipe 18 x 1 8 pipe bend, pipe angle pvc 20x1. There are many different types of systems that can cause minor losses in a pipe. Head loss in pipe flow major and minor losses me 322 lecture slides, winter 2007 gerald recktenwald. Consider pipes in parallel discharging water from a tank with higher water level to another with lower water level, as shown in the figure. Energy losses in pipes used for the transportation of fluids water, petroleum, gas, etc. In case of a long pipeline, the minor losses maybe negligible compared to the friction losses, howe.