Comparison of methods for predicting head loss in turbulent pipe flow of nonnewtonian fluids article pdf available in transactions of the institute of measurement and control 61. For example, it may be desired to predict the rate of flow along a proposed pipe connecting two reservoirs at different levels. A galvanized iron pipe with a roughness height of 0. For any pipe system, in addition to the moodytype friction loss computed for the length of pipe. Friction loss lbs per square inch friction head feet v elocity feet per second friction loss. Steel pipes tuberculate and corrode in much the same manner as castiron pipes.
Present model is found to be equally valid for both cases of commercially available pipes and nikuradse experiments on sand roughened pipes. Velocity, friction head and pressure drop per 100 feet of pipe, interior smooth. The darcy weisbach equation relates frictional head loss or pressure drop in pipe flow to the pipe diameter, pipe length, average flow velocity, pipe roughness, and reynolds number. In the experiment described below, we investigate the frictional resistance to flow along a long straight pipe with smooth walls.
The general behavior of turbulent pipe flow in the presence of surface roughness is well established. Schedule 40 head loss per 100 values are usually used for other wall thicknesses and standard iron pipe size o. 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. It used by engineers in over 75 countries worldwide, to model pipe systems where the flow rates, pressure losses, and pumping requirements of the system need to. In direction of flow, due to friction cause by viscosity of the fluid we have v2. These losses are given in terms of velocity pressure. Introduction the head loss hf due to friction undergone by a fluid motion in a pipe is usually. The common formula for calculating the loss of head due to friction is darcys one. Under turbulent flow, the friction loss is found to be roughly proportional to the square of the flow velocity and inversely proportional to the pipe diameter, that is, the friction loss follows the phenomenological darcyweisbach equation in which the hydraulic slope s can be expressed. By observation, the head loss is roughly proportional to the square of the flow rate in most engineering flows fully developed, turbulent pipe flow. Be able to use the course spreadsheet to make pipe flowfriction factor. Spreadsheets for pipe flowfriction factor calculations harlan h. Energy losses in pipe flow major energy loss due to friction minor energy losses a. We begin with some results that we shall use when making friction loss calculations for steady, fully developed, incompressible, newtonian flow through a straight circular pipe.
It takes something to move over a rough surface 2 pipe flow. Friction pressure loss values are computed from the. Because pressure is the form of energy in the pipe, pressure drops due to pipe friction. There are many types of losses of head for flowing liquids such as friction, inlet and outlet losses. Pipe flow friction factor calculations with excel harlan h. The following charts provide reference data for the loss of pressure due to friction in various pipe sizes that should be. Enter the flow rate, internal pipe diameter, and the type of pipe from the list supplied. Pipe flow expert user guide pipe flow software for pipe. Friction loss per 100 coefficient of retardation based on pipe material flow volume gpm inside diameter of pipe v q d p p ff p software, the irrigation system design calculator information.
Friction loss per 100 coefficient of retardation based on pipe material flow volume gpm inside diameter of pipe v q d p p ff p software, the. All real systems that are in motion suffer from some type of loss due to friction. 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. Hose water flow pressure loss water flow and pressure loss due to friction in hoses iso 4427 pe pipes for water supply dimensions polyethylene pipe dimensions according european standards iso 4437 pe pipes for gaseous fuels supply dimensions dimmensions of pe pipes for gaseous supply according iso 4437. Friction in pipes and passages fluid mechanics ltd. Pipe flow expert verification results pipe flow software. The friction loss in a pipe apparatus allows students to study the change in the laws of resistance for laminar to turbulent flow and find the critical reynolds number. Noncircular pipe friction the frictional head loss in circular pipes is usually calculated by using the darcyweisbach formula with a darcy friction factor.
The darcy weisbach equation can also be considered to be an equation giving frictional head loss or pressure drop as a function of the friction factor, pipe length pipe diameter, and the velocity head, where. Losses are calculated on the basis of flow rates in circular pipes, the internal diameter of the pipe, the length of the pipe, and the type of pipe. Note that even for smooth pipes the friction factor is not zero. Rain bird supports the use of trained irrigation professionals for system design and installation. Engineering manual friction of water in pipes continued gallons per minute velocity ft. Head loss from pipe friction 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. In fluid flow, friction loss or skin friction is the loss of pressure or head that occurs in pipe or duct flow due to the effect of the fluids viscosity near the surface of the pipe or duct. In a laminar flow, the pipe friction loss increases linearly with the flow velocity, and it depends only on the viscosity of the liquid. Many of the calculations require an iterative solution, so they are especially suitable for an excel. Abstract this technical note describes diagrams of friction factor for pipe ow that have been prepared using, mainly, the equations that lewis moody. When a liquid or gas flows along a pipe, friction between the pipe wall and the liquid or gas causes a pressure or head loss. Noncircular pipe friction pipe flow software for pipe. Friction losses in pipe fittings resistance coefficient k.
Oct 02, 2015 now that you know already how to calculate friction factor, is time to calculate friction loss due to flow in pipes. Where delta p is the pressure drop due to laminar flow through a pipe, and q is the volumetric flow. This is a result of the noslip boundary condition that requires any. This friction loss calculator employs the hazenwilliams equation to calculate the pressure or friction loss in pipes. For circular pipes the inner pipe diameter is used is used to calculate the reynolds number and to calculate the relative roughness of the pipe, which are both used to calculate the darcy. The energy is then lost through the walls of the pipe. The bernoulli equation that we worked with was a bit simplistic in the way it looked at a fluid system.
Friction loss in pipes applied fluid dynamics class 032. Pdf comparison of methods for predicting head loss in. Jim mcgovern department of mechanical engineering and dublin energy lab dublin institute of technology, bolton street dublin 1, ireland. This pressure or head loss is an irreversible loss of the fluids potential energy. A table is also included showing the friction loss through various. Friction loss along a pipe introduction in hydraulic.
In this example, calculate the total friction loss in a pipeline. The values of c i given in this handbook include the local pressure losses in the. Flow in pipe is always creating energy loss due to friction. Most pipe systems consist of considerably more than straight pipes. Associate professor, mechanical and materials engineering department portland state university, portland, oregon. Hose water flow pressure loss water flow and pressure loss due to friction in hoses. Department of chemical and biomolecular engineering.
Use of excel for pipe flowfriction factorhead loss calculations. These additional components add to the overall head loss of the system. Pipe friction loss in this example, calculate the total friction loss in a pipeline. With the head loss of each section of pipe being the pressure drop across the pipe divided by the product of the density of the fluid and gravity, equation 2 can be used to calculate the experimental friction factor for each flow rate. Spreadsheet use for pipe flow friction factor calculations. What is pressure loss in pipe friction loss in pipe. 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. Pipe friction loss calculations pipe flow software. Pipe friction loss calculations flow of fluid through a pipe is resisted by viscous shear stresses within the fluid and the turbulence that occurs along the internal pipe wall, which is dependent on the roughness of the pipe material. Select the appropriate k value for such and select d and f for schedule. The data at hand indicate a value of 110 for new pipe, decreasing in the course of about ten years to 100. Table 3 friction losses through pipe fittings in terms of equivalent lengths of standard pipe size of pipe small dia. Such losses are generally termed minor losses, with. Calculating this loss is fundamental to the design of any pipeline system.
Pipe flow expert results data verification 4 introduction pipe flow expert is a software application for designing and analyzing complex pipe networks where the flows and pressures must be balanced to solve the system. As each community, county, state or local ahj adopts this standard. Friction loss along a pipe suny polytechnic institute. You will also explore effects of the skin friction, pipe network configuration, and pipe fittings tees, elbows, etc.
A graphical depiction of friction loss through pvc pipe developed from the pvc table is presented to provide a quick reference. That is, there is a head loss in any pipe, no matter how smooth the surface is made. Standard elbow medium radius elbow long radius elbow 45 elbow tee return bend gate valve open globe valve open angle valve open length of straight pipe giving equivalent resistance flow. If the flow is laminar then the friction parameter f is calculated with the laminar flow equation 3. The incompressible steady flow energy equation, including friction loss, would generalise to 22 12,1,2 2212 mm f ppuu zzh gg g g. In addition to pipe friction loss, there are losses due to changes in pipe crosssection and also due to fittings such as valves and filters.
The rate of flow along the pipe is controlled by a needle valve at the pipe exit, and is measured by timing the collection of water in a measuring cylinder the discharge being so small as to make the use of the h1 hydraulic bench weighing. Reynolds number, laminar flow, turbulent flow and energy losses due to friction 2005 pearson education south asia pte ltd 8. Gradually varied flow profiles physical laws governing the head variation in open channel flow 1 gravity so is the driving force for flow 2 if so sf then dedx 0 and flow is uniform normal depth 3 gravity so is balanced by friction resistance sf and longitudinal adjustment in specific energy dedx. It used by engineers in over 75 countries worldwide, to model pipe systems where the flow rates, pressure losses, and pumping requirements of the system need to be calculated. The power required to overcome friction is related to the pressure drop through. Energy loss is primarily a function of pipe diameter and. 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.
Control volume of a steady, fully developed flow between two sections in an inclined pipe. Example lab report losses civl2310 fluid mechanics. In mechanical systems such as internal combustion engines, the term refers to the power lost in overcoming the friction between two moving surfaces, a different phenomenon. For older pipes, as far as the present data go, steel. P 8q pl sr 4 this equation is known as the hagenpoiseuille equation. Technical articles about pipe pressure drop calculations. Leave pipe length as 100 to get the friction loss per 100 mft of pipeline.
Velocity of flow values is computed using the general. The major loss is that due to frictional resistance of the pipe, which depends on the inside roughness of the pipe. Iso 4437 pe pipes for gaseous fuels supply dimensions dimmensions of pe pipes for gaseous supply according iso 4437. The principle examined in this experiment was how the frictional flow of a fluid in a pipe relates to the relationship with the fluids reynolds number. For horizontal pipe, with constant diameter this loss may be measured by height. Use the friction factor to calculate frictional head loss. Friction losses are a complex function of the system geometry, the fluid properties and the flow rate in the system. Pdf there is evidence in literature that friction factors smoother than smooth, that is smaller. Flow and pressure loss calculations produced by the pipe flow expert software can be verified by comparison against published results from a number of wellknown sources. Table 3 friction losses through pipe fittings in terms of equivalent lengths of standard pipe size of pipe.
Consider fully developed flow through a constantarea pipe between section 1 and 2 in figure 3. Friction loss in fittings watts water technologies. General equation for pressure drop, known as darcys formula expressed in meters of fluid is. Determine l friction loss in pipe fittings in terms of equivalent length in feet of straight pipe. Pipe flowfriction factor calculations with excel harlan h. Energy loss can be measured like static pressure drop in the direction of fluid flow with two gauges. Pdf friction losses in largediameter pipes researchgate. In a bend, in addition to the head loss due to pipe friction, a loss due to the change in flow direction is also produced.
Table 3 friction losses through pipe fittings in terms of. These calculations can be conveniently carried out with an excel spreadsheet. Friction loss technical ulletin february 28, 2017 nfpa, 2016, 23. Doc mec2404 frictional flow in pipe lab report done by. Introduction several kinds of pipe flow calculations can be made with the darcyweisbach equation and the moody friction factor. Pressure loss in pipe, which are associated with frictional energy loss per length of pipe depends on the flow velocity, pipe length, pipe diameter, and a friction factor based on the roughness of the pipe, and whether the flow is laminar or turbulent i. Line 3 and dotted line 3 show that in going from a pipe 2. Pipe pressure drop software from pipe flow for friction loss, flow rates and pipe diameter sizing. Head loss in pipe flow major and minor losses me 322 lecture slides, winter 2007 gerald recktenwald.
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