Recognize the distinction between major losses and minor losses in a pipe system, 2. To find the major losses throughout the system, a technovate fluid circuit system was used. 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. There are many different types of systems that can cause minor losses in a pipe.
This is different from major losses because those come from friction in. Aug 24, 2016 want to see more mechanical engineering instructional videos. Major losses, denoted by hmajor sometimes hf, are those due to frictional losses through sections of constant diameter pipe, in which the flow is fully developed. Calculations to determine system pressure drop require experimental data to account for friction losses occurring in valves and fittings steffe and others. These pressure drops provide a way to find the friction factor acting on the pipe and the velocity of a flow. Minor losses is a term used to describe losses that occur in fittings, expansions, contractions. 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 pipe flow are a major part in calculating the flow, pressure, or energy reduction in piping systems. Losses in bends module fme05, shown in figure 5, were used to determine the major and minor losses that pipes create.
The length of the pipe 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. Major and minor losses due to pipe diameter and fitting. Major losses are associated with frictional energy loss that is caused by the. Head loss in pipe flow system due to various piping components such as valves, fittings, elbows, contractions, enlargement, tees, bends and exits will be termed as minor head loss and will be indicated by h lminor. Neglecting minor losses, determine the flow rates in the pipe system. Liquid moving through pipes carries momentum and energy due to the forces acting upon it such as pressure and gravity. Two types of energy loss predominate in fluid flow through a pipe network. The major and minor losses exercise was performed to gather an understanding of the effect of pipe diameter, pipe material, and flow rate on major energy losses in a flowing fluid. In addition, the exercise was performed to understand the effect of minor energy losses due to. Energy losses in pipe flow major energy loss due to friction minor energy losses a.
These minor losses cause nonuniformities in the flow path, resulting in small energy losses due to. The minor losses are any head loss present in addition to the head loss for the same length of straight pipe. Head loss in pipe flow system due to various piping components such as valves, fittings, elbows, contractions, enlargement, tees, bends and exits will be termed as minor head loss and will be indicated. Jun 10, 2015 where, hlm minor loss k minor loss coefficient v mean flow velocity g v khlm 2 2 type k exit pipe to tank 1. For the minor losses, the effect of different fitting types were calculated. Major losses occur due to friction within a pipe, and minor losses occur at a change of section, valve, bend or other interruption. 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. Additional components valves, bends, tees, contractions, etc in pipe flows also contribute to the total head loss of the system.
For friction head loss, the friction factor is 64re for laminar flow, and a more complex formula for turbulent flow. Energy equation pressure head loss in ducts, tubes and pipes. Head losses, frictional head losses, major head losses, minor head. The major friction loss in a pipe or tube depends on the flow velocity, pipe or duct length, pipe or duct diameter, and a friction factor based on the roughness of the pipe or duct, and whether the flow us turbulent or laminar the reynolds number of the flow.
Indication of laminar or turbulent flow the term fl tflowrate shldbhould be e reprepldbr ldlaced by reynolds number,where v is the average velocity in the pipe, and l is the characteristic dimension of a flow. Head loss in pipe flow system due to viscous effect i. For a given discharge q, pipe flow at any location can be described by the pipe cross section the pipe elevation, the pressure, and the flow velocity in the pipe. Total head loss in pipe or duct systems engineering toolbox. Frictional losses in pipe flows the viscosity causes loss of energy in flows which is known as frictional loss. 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.
If the pipe is long enough the minor losses can usually be neglected as they are much smaller than the major losses. Bends, expansions, contractions, valves, fittings, and meters are a few of them. Want to see more mechanical engineering instructional videos. Minor losses in pipe flow florida international university. Using the energy equation you can determine the minor loss coefficients kl by monitoring the pressure drop across the various pipe system features. The pressure loss in a tube or duct due to friction, major loss, can be expressed as. For the technovate, the height differences in tube 1 and tube 2, the two closets to the system of the four tubes, started at a difference 25 inches at maximum water flow. Major losses, 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. 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. Refers to full water flow in closed conduits of circular cross sections under a certain pressure gradient.
Fundamentals of fluid mechanicsfluid mechanics chapter 8 pipe. Just as certain aspects of the system can increase the fluids energy, there are components of the system that. Energy lost due to friction in pipes is commonly termed major losses and occurs due to the frictional characteristics of the pipe or duct material acting on the flowing fluid. These losses represent additional energy dissipation in the flow, usually caused by secondary flows induced by curvature or recirculation. Elevation h of a particular section in the pipe is usually measured with respect to a. Energy lost due to a change in velocity inside of a fitting or valve is generally small in comparison to major losses, and is commonly referred to as minor losses. Example lab report losses civl2310 fluid mechanics uon.
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. In this practical you will investigate the impact of major and minor losses on water flow in pipes. In general, the friction factor is a function of the reynolds number and the nondimensional surface roughness, ed. 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. Major losses, colebrookwhite equation, jain equation, moody diagram, minor losses. May 15, 2018 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. The major loss is that due to frictional resistance of the pipe, which depends on. The value of k is typically provided for various devices. I understand how the head loss due to friction is different for the two regimes. 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 cupipe 18 x 1 8 pipe bend, pipe angle pvc 20x1. Example lab report losses civl2310 fluid mechanics. You created this pdf from an application that is not licensed to print to.
What is major minor losses in a flow through pipe answers. By know the major head losses due to pipe diameter over a length of pipe and the minor head losses caused by pipe fittings can cut down on cost and raise the overall efficiency of a system. Losses are proportional to velocity of flow, geometry of device. Even though they are termed minor, the losses can be. Experimentally, two sections of pipe with diameters of 0. 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 hl major. 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 major head loss for a single pipe or duct can be expressed as. Head loss in pipe flow major and minor losses me 322 lecture slides, winter 2007 gerald recktenwald.
Head losses in pipes pennsylvania state university. Minor losses are head losses due to flow through fittings and are related by loss coefficient. Major and minor losses in pipes mechanical engineering. Hi, i need clarification on the difference in head loss for turbulent flow and laminar flow. Head losses in pipes penn state mechanical engineering. The major loss is that due to frictional resistance of the pipe, which depends on the inside. Apr 05, 2018 flow through pipes fully developed flow properties of fully developed flow darcywiesbach formula losses in flow through pipes major losses minor losses sudden expansion sudden contraction tee. Entrance length required for fully developed flow in a pipe qm. Flow through pipes fully developed flow properties of fully developed flow darcywiesbach formula losses in flow through pipes major losses minor.
Major losses the major head loss in pipe flows is given by equation 3. This is different from major losses because those come from friction in pipes over long spans. Friction head losses in straight pipes of different sizes can be investigated over a range of reynolds. There are many types of losses of head for flowing liquids such as friction, inlet and outlet losses. Expansions are defined as when the flow in a pipe goes from a small area to a. Major losses are associated with frictional energy loss that is caused by the viscous effects of the medium and roughness of the pipe wall. Empirical data on viscous losses in straight sections of pipe are correlated by the dimensionless darcy friction factor f. In direction of flow, due to friction cause by viscosity of the fluid we. For the major losses, the water flow was pushed through a small diameter pipe and a large diameter pipe.
Head loss in pipe flow major and minor losses portland state. Major losses are expressed in reference books in terms of a nondimensional friction factor, f, defined as major 2 2 h f lv dg 1. Losses are proportional to velocity of flow, geometry of device 2 h k v g 2 l. Minor losses in pipes come from changes and components in a pipe system. The major head loss is given by the following equation h major f ld v22g the minor head loss is given by the following equation h minor. The head loss in various pipe components, termed the minor loss and denoted hlminor. The head loss in various pipe components, termed the minor loss and denoted hl minor. This loss can be calculated using the moody chart or colebrook equation.
Most calculated quantity in pipe flow is the head loss. 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. Although they often account for a major portion of the head loss, especially in process piping, the additional losses due to entries and exits, fittings and valves are traditionally referred to as minor losses. Head loss is necessary to determine the pumping power requirement of a system and is equivalent to the additional height that the fluid needs to raised by a pump in order to overcome the major and minor losses in the pipe cengel and cimbala, 2010.
Gradual expansions or contractions the major losses may not be so minor. The module contained a long elbow, a sudden enlargement, and sudden. Experiment image and source credits minor loss in pipe or duct components. Minor head loss head loss or pressure loss due to components as valves, bends, tees and the like in the pipe or duct system. Major losses, colebrookwhite equation, jain equation. Minor in comparison to friction losses which are considered major. The resistance to flow in a pipe is a function of the pipe length, pipe diameter, mean.