Introduction to structural mechanics mit opencourseware. Practical advice for making acquisitions succeed financial times management briefings rankine, denzil on. The ideal rankine cycle ts diagram of the ideal rankine cycle 3 determine the thermal efficiency of the ideal rankine cycle. The maximum stress criterion, also known as the normal stress, coulomb, or rankine. View homework help chapter 9 rankine cycle problems solutions.
Maximum principal stress theory also known as rankines theory. Because of higher pressure limitation at the inlet of turbine efficiency of rankine cycle is low. In retaining wall problems, active earth pressure contributes to the failure of the wall. A study of cultural differences in crossborder mergers. A schematic of the components of a rankine cycle is shown in figure 8. Slope stability and exact solutions for cohesive critical. The theory is based on a limiting energy of distortion, i.
Steam turbine inlet temperature 500 0c to 800 c ii. Maximum shear stress tresca theory for ductile materials. With regards to the phenomenon of reflecting shock waves, it. A stress system in the interior of the envelop is considered safe for design purposes, the failure relation can be modified to include a factor of safety n. A theory of yielding and failure for homogeneous and isotropic materials is given. The following cases of active earth pressure on cohesionless backfill will now be considered. Rankinehugoniot relations for steady onedimensional flow of a combustible gas that burns to completion, equations relating initial and final conditions are readily derived from conservation equations. Pdf determination of distribution and magnitude of active earth pressure is. Organic rankine cycles are a modification of the well known clausius rankine cycle the use of organic fluids offer various advantages the orc technology for electricity production from biomass and geothermal heat is state of the art orcs are also suitable for wasteheat recovery and power.
Rankine hugoniot relations for steady onedimensional flow of a combustible gas that burns to completion, equations relating initial and final conditions are readily derived from conservation equations. Select multiple pdf files and merge them in seconds. Introduction the relations describing the changes that take place across shock waves are named after rankine 17 and hugoniot. Maximum shear stress theory or guest and trescas theory 3. Analysis of rankine cycle and its utility in thermal power plant a theoretical approach 54 regarded as a control volume, operating at steady state. The stress states of soil elements a and b are called the rankine active state and the rankine passive state, respectively named after the first developer of this theory rankine, 1857. Later it was extended to include cohesive soil by bell in 1915. Accomplish this by drawing the failure envelope in a principal stress space and plotting the principal stresses for this cylinder. It is assumed that students doing this tutorial are already familiar with complex stress theory covered in tutorial 1. Lecture 12 earth pressure and sturucture rankine theory 1 free download as powerpoint presentation. Rankine s theory is suitable for brittle materials. Fluid mechanics, sg2214, ht20 october 7, 20 exercise 10.
Apr 30, 2014 various theory of failure maximum principal stress theory rankines theory maximum principal strain theory st. A combustion wave will travel down the tube starting from. It was also used to study the performance of reciprocating steam engines. Mohrs theory suggests that failure occurs when mohrs circle at a point in the body exceeds the envelope created by the two mohrs circles for uniaxial tensile strength and uniaxial compression strength. Limited by the saturation pressure corresponding to the cooling medium ex. Theories of failure maximum shear stress theory to use this theory for either two or threedimensional static stress in homogeneous, isotopic, ductile materials, first compute the three principal stresses 1, 2, 3 and the maximum shear stress as 12 max 2 max min 2 pp then compare the maximum shear stress to the failure criterion. The methods suggested by them are based on theory of classical earth pressure. Optimize a design comparing different failure theories. Hence, the present investigation has selected the following range of operating parameters to contribute to the analysis of rankine cycle in supercriticalultra supercriticaladvanced ultra supercritical ranges. Rankines theory maximumnormal stress theory, developed in 1857 by william john macquorn rankine, is a stress field solution that predicts active and passive earth pressure.
The efficiency of an ideal engine operating on the rankine cycle under specified conditions of steam temperature and pressure. Pr pe pc where pe is the euler buckling load and pc is the crushing compressive yield load aya. Exact solution for cohesive critical tapers from pole construction in mohr plane. Several theories are available however, only four important theories are discussed here. Review of rankine limit equilibrium states of stress. This was postulated by pauker a military engineer in 1850 and then modified by bell in 1915. In practice, however, most column struts suffer plastic knockdown and the experimentally obtained buckling loads are much less than the euler predictions. Rankines assumptions for earth pressure theory for active.
Rankine s theory maximumnormal stress theory, developed in 1857 by william john macquorn rankine, is a stress field solution that predicts active and passive earth pressure. Figure 3 shows a graph combining all analytical theories on active earth pressure. The maximum distortion energy failure theory assumes failure by yielding in a more. A failure theory is a criterion that is used in an effort to predict the failure of a given material when subjected to a complex stress condition. Material failure theory is the science of predicting the conditions under which solid materials fail.
Design methodology for hydraulic ram pump hydram seemin sheikh1, c c handa 1 and a p ninawe corresponding author. Rankine cycle in subcritical range of operating parameters. Combining 18,19 at ra gives the pressure for initial yielding as. Burgers equation consider the initialvalue problem for burgers equation, a. According to this theory, in simple tensile test, when maximum principle stress reaches the value of yield point, the material subjected to complex stresses fail. Let assume the rankine cycle, which is the one of most common thermodynamic cycles in thermal power plants. Second law analysis of rankine cycle the rankine cycle is not a totally reversible cycle, it is only internally reversible, since heat transfer through a finite temperature difference between the furnace and the boiler or between the condenser and the external medium can results in irreversibilities. Earth material or any other granular material like sand, cement grains, etc.
Since pa is horizontal, there is no vertical component of the force. Velocityandpressureofwind description of winds table of varying velocities at differentlevels diagram of wind pressure general. Retaining walls rankines theory pressures on retaining walls due to granular materials rankines theory. Rankine cycle equations and calculation let assume the rankine cycle, which is the one of most common thermodynamic cycles in thermal power plants. In this paper, classical shock waves shall be referred to as rhshocks. Comparative performance of reheat and regenerative steam. Maximum principal stress theory is represented as shown below. Outline of a theory of nonrankinehugoniot shock wave in. Investigation on the combined rankineabsorption power and. No yield point in brittle materials sudden failure fs on failure load. Lecture 12 earth pressure and sturucture rankine theory 1. To enhance the efficiency of rankine cycle, reheater and regenerators are used.
Decrease condenser pressure good news bad news increase in the net work. The population of a study consisted of 9 banks that have merged or acquired in the period 2010 to may 2017 in kenya. The rankine cycle is a model used to predict the performance of steam turbine systems. Mohr 2 put coulombs failure result into a form allowing easy utility.
The pump and turbine have isentropic efficiencies of 0. For element b to reach the failure state, the lateral effective stress must be greater than the vertical effective stress, as shown if fig. Scribd is the worlds largest social reading and publishing site. Retaining walls in theory and practice, a textbook for students. Rankine cycle consists of two isentropic processes and two isochoric processes. This formula has been widely used and is discussed fully in 2. Calculate the thermal efficiency of a simple rankine cycle for which steam leaves the boiler as saturated vapor at 3 x 10 6 nm 2 and is condensed to saturated liquid at 7000 nm 2. Maximum principal stress theory also known as rankine s theory 2. Cold liquid at initial temperature is pressurized reversibly to a high pressure by a pump. The cycle is shown on, and coordinates in figure 8. Pressure vessels stresses under combined loads yield criteria for. This theory is due to rankine and assumes that failure will occur when the. Contribute to rankinedevrankine development by creating an account on github. The rankine cycle is an idealized thermodynamic cycle of a heat engine that converts heat into.
Tell a friend about us, add a link to this page, or visit the webmasters page for free fun content. The study was collected using questionnaires to collect primary data. Dry or moist backfill submerged backfill partly submerged backfill backfill with uniform surcharge backfill with sloping surcharge. The properties at each state of the ideal rankine cycle can be obtained from the water table. It assumes that the soil is cohesionless, the wall is frictionless, the soilwall interface is vertical, the failure surface on which the soil moves is planar, and the resultant force is angled parallel to the backfill. In this case assume a simple cycle without reheat and without with condensing steam turbine running on saturated steam dry steam. Rankine efficiency article about rankine efficiency by the. Increase in qh but this is small compared to the increase in the net work. Rankine cycle, steamturbine, efficiency, feed water heater fwh, irreversibility, reheat cycle, regeneration, condensers introduction. The rankine cycle was devised to make use of the characteristics of water as the working fluid.
A single stress component z can exist on the zaxis and the state of stress is still called 2d and the following equations apply. Consider a premixed flammable mixture in a long tube ignited from one end. We can now combine the individual load cases to obtain the stress elements. An analysis of a thermal power plant working on a rankine. Stability criteria for gravityloaded coulombplastic layers deposited on a weak base. Cold liquid at initial temperature is pressurized reversibly to a high pressure by a. The rankine cycle is an idealized thermodynamic cycle of a heat engine that converts heat into mechanical work while undergoing phase change. A comprehensive theory of yielding and failure for isotropic.
Conventional energy is also a great concern for environment. Mohrs theory is often used in predicting the failure of brittle materials, and is applied to cases of 2d stress. The mohr theory of failure, also known as the coulombmohr criterion or. It assumes that the soil is cohesionless, the wall is frictionless, the soilwall interface is vertical, the failure surface on which the soil moves is planar, and the. Earth pressure coefficients for coulombplastic rankine states in sloping half space. The greatest principal stress theory rankine this simply states that in a complex stress situation, the material fails when the greatest principal stress equals the maximum allowable value. Axisymmetric ow with vorticity and rankine vortex the rankine vortex a simple model for a vortex is given by the combination of a rigidbody rotation within a core, and a decay. Rankine gordon equation predictions of buckling loads by the euler formula is only reasonable for very long and slender struts that have very small geometrical imperfections. Theory the rankine cycle is the most common of all power generation cycles and is diagrammatically depicted via figures 1 and 2. Rankine theory is applied to those materials which are strong in shear but weak in compression or tension. Rankine and carnot cycle the rankine cycle is a heat engine with a vapour power cycle.
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