Hydrodynamic lubrication nptel. B. The structure of the bearing and the nature of fluid flow determine the loads that can be supported. Modeling systems as hydrostatic squeeze film and Elasto-hydrodynamic lubrication will be studied as infinite and later Nov 11, 2012 · Tribology by Dr. When two surfaces, containing viscous fluid in between, approach towards each other the viscosity of fluid resists this motion and builds fluid pressure to prevent contact between the surfaces. This document contains a list of 25 questions related to tribology, the branch of science pertaining to friction, wear, and lubrication. 4. Symbols - (Including fundamentals of fluid flow, fluids etc. 4 Hydrostatic and Hydrodynamic Systems A hydrostatic system uses fluid pressure to transmit power. R. 5. Capillary Fluid (incompressible) Flow and Hydrodynamic Lubrication tutorial of Fundamentals of Industrial Oil Hydraulics and Pneumatics course by Prof Prof. in Modeling systems as hydrostatic, squeeze film and elasto-hydrodynamic lubrication will be studied as infinite and later finite structures. Some of the questions address topics like the relationship between lubrication efficiency and safety/reliability, types of magnetic We can classify that lubrication theory based on these four basic characteristics 1 is hydrodynamic lubrication another is hydrostatic lubrication and then hydro magnetic lubrication, last 1 is thermodynamic lubrication. In hydrostatic lubrication external pressure is supplied to separate two surfaces, while relative velocity between two surfaces is used to generate liquid pressure between two surfaces. NPTEL____Mechanical_Engineering_-_Tribology - Free download as PDF File (. NPTEL Phase II :: Tribology Lecture 7 - Lubrication regimes and film thickness calculations Lecture 8 - Mixed Lubrication Lecture 9 - Hydrodynamic Lubrication Theory Tribology by Dr. Therefore in hydrodynamic lubrication hmin ן U0. Abrasion of tribo-surfaces due to free particles. If there is a some lubricant, which Courses NPTEL STARS Coordinators NPTEL Testimonials Exam Schedule Help Videos More And whenever we talk about hydrodynamic lubrication or elastohydrodynamic lubrication, viscosity is going to play major role. We said many times it reduces the failure possibility due to the certain change in load certain, change in lubrication conditions, certain change in misalignment. (from nptel. 5. The system creates high pressure, and through a transmission line and a control element, this pressure drives an actuator (linear or rotational). Here, we combine elastic Lecture 10 - Wear Analysis Lecture 11 - Lubrication and Lubricants Lecture 12 - Boundary Lubrication Lecture 13 - Lubrication Mechanisms Lecture 14 - Hydrodynamic Lubrication Lecture 15 - Lubricant Classifications Lecture 16 - Solid and Semi Solid Lubricants Lecture 17 - Liquid Lubricants Lecture 18 - Lubricant Additives Lecture 19 - Fluid Film So, first let us classify the fluid film lubrication. And naturally, we need to choose proper lubricating oil having appropriate viscosity. in Elastohydrodynamic lubrication (EHL) is a mode of fluid-film lubrication in which hydrodynamic action is significantly enhanced by surface elastic deformation and lubricant viscosity increases due to high pressure. The pump used in hydrostatic systems is Liquid lubrication is more common compared to gaseous lubrication. Modeling systems as hydrostatic, squeeze film and elasto-hydrodynamic lubrication will be studied as infinite and later finite structures. In case of hydrodynamic, you can see it is a converging wedge shaped geometry and there is a applied load and it is having the tangential velocity. This transition from static rest to dynamic, full-film lubrication is fundamental to Mechanical-Syllabus NPTEL - Free download as PDF File (. Theory of Hydrodynamic Lubrication Thin film of oil, confined between the interspace of moving parts, may acquire high pressures up to 100 MPa which is capable of supporting load and reducing friction. 3) develops its force by the same action, except that the surfaces are curved. 58), therefore careful selection of viscosity is important. Hydrostatics deals with the mechanics of still fluids and uses the theory of equilibrium conditions in fluid. This course will cover the derivation of Navier-Stokes equations, exact solutions for simplified configurations, creeping flows , Stokes’s first and second problems, laminar boundary layers, wall-bounded and free-shear Tribology by Dr. COURSE OUTLINE Tribology deals with design of fluid containment systems like seals and gasket, Lubrication of surfaces in relative motion to achieve reduced friction and wear. Abrasion due to asperities on tribo-surfaces. This situation is often beneficial and lubrication is used to reduce friction and/or wear of rubbing solids with the aid of liquid (or semi-solid) lubricant. (Refer Slide Time: 01:44). 5 is used. The theory is applied for capillary flow as well as to develop hydrodynamic lubrications theory in sliding contact bearing which include the slipper pad and the journal bearing lubrication. In Elastohydrodynamic lubrication we consider the viscosity thickening due to increase in pressure, which in turn increases the fluid pressure. Basic Components. M. in In hydrodynamic lubrication, increase in viscosity increases load capacity but also increases friction and temperature (Eq. Fluid may be gas or liquid. 6. in Tribology by Dr. It is important to consider the thermal effect because several lubricants show reduction in fluid viscosity on increasing temperature, which may reduce load carrying capacity Lecture 14 - Hydrodynamic LubricationLecture 14 - Hydrodynamic Lubrication HomePrevious Lecture 11 - Lubrication and Lubricants Lecture 12 - Boundary Lubrication Lecture 13 - Lubrication Mechanisms Lecture 14 - Hydrodynamic Lubrication Lecture 15 - Lubricant Classifications Lecture 16 - Solid and Semi Solid Lubricants Lecture 17 - Liquid Lubricants Lecture 14 - Hydrodynamic LubricationLecture 14 - Hydrodynamic Lubrication HomePrevious Lecture 14 - Hydrodynamic LubricationLecture 14 - Hydrodynamic Lubrication HomePrevious Lecture 26 - Thermo Hydrodynamic LubricationLecture 26 - Thermo Hydrodynamic Lubrication Home Lecture 14 - Hydrodynamic LubricationLecture 14 - Hydrodynamic Lubrication HomePrevious NPTEL IITm NPTEL IITm NPTEL IITm NPTEL IITm Lecture 9 - Hydrodynamic Lubrication TheoryNPTEL Video Course : NOC:Data-Enabled Tribological Engineering: From Experiments to Predictive Models Lecture 10 - Design Considerations for Hydrodynamic Lubrication Systems Lecture 14 - Hydrodynamic Lubrication Home Previous Next Thumbnails Acadooghostwriter. Hydrostatic and hydrodynamic lubrications are two mechanisms of liquid lubrications. in) Anyway, we will look into the hydrodynamic lubrications and the pressure field in case of capillary passage. in NPTEL IITm NPTEL IITm The analysis of a hydrodynamic lubrication problem with allowance for viscous heating and dissipation of thermal heat is commonly known as thermo-hydrodynamic lubrication. This document provides course details for two engineering courses: 1) Engineering Mechanics, which covers topics like statics, dynamics, friction, and vibrations through 16 modules. inmore Lecture 6 - Principles of Lubrication, types of Lubricants and their properties Lecture 7 - Lubrication regimes and film thickness calculations Lecture 8 - Mixed Lubrication Lecture 9 - Hydrodynamic Lubrication Theory Lecture 10 - Design Considerations for Hydrodynamic Lubrication Systems Lecture 11 - Elastohydrodynamic Lubrication 1. Squeeze is English word, meaning act of gripping and pressing firmly. Fluid includes all gases, liquids and easy flowing solids. Michell, works on the principles based on the theory of hydrodynamic lubrication . This course focusses largely on viscous flows in the incompressible regime. So, you can see that we can classify this fluid film lubrication as hydrodynamic, squeezed film, and hydrostatic. Early methods of measuring the film thickness NPTEL __ Mechanical Engineering - Tribology2 - Free download as PDF File (. # 26 Thermo – Hydrodynamic Lubrication Welcome to twenty sixth lecture of video course on Tribology. e. Lubrication makes relative motion between COURSE OUTLINE Tribology deals with design of fluid containment systems like seals and gasket, Lubrication of surfaces in relative motion to achieve reduced friction and wear. 2) Basic Thermodynamics, which covers thermodynamics relations, properties of pure substances and mixtures Lecture 5 - Capillary Fluid (incompressible) Flow and Hydrodynamic Lubrication 1x Search within video (e. pdf), Text File (. Elastohydrodynamic Lubrication – or EHL – is a lubrication regime (a type of hydrodynamic lubrication (HL)) in which significant elastic deformation of the surfaces takes place and it considerably alters the shape and thickness of the lubricant film in the contact. in Due to such extreme operating conditions there is hardly any possibility of hydrodynamic lubrication, so grease mixed with solid lubricants (i. N. nptel. g: "acoustic", "hydraulics" or "friction") Speech Recogniser Status: Not Recognising Search and Play Video / Home Previous Next The Genesis and Mechanics of the Hydrodynamic Wedge in Journal Bearings Section 1: The Formation Sequence: From Static Contact to Dynamic Lift The formation of a load-bearing hydrodynamic wedge in a journal bearing is not an instantaneous event but a sequential process that traverses distinct physical regimes. Lecture 5 - Capillary Fluid (incompressible) Flow and Hydrodynamic Lubrication Due to fluid pressure two surfaces get separate and minimum fluid film exists. An attempt has been made to clear Tribology by Dr. ) Hydraulic valves General Purpose+Servo valves + NPTEL IITm NPTEL IITm Tribology by Dr. com NPTEL IITm NPTEL IITm COURSE OUTLINE Introduction to Hydraulic and Pneumatic Systems. in/nocmore COURSE OUTLINE Tribology deals with design of fluid containment systems like seals and gasket, Lubrication of surfaces in relative motion to achieve reduced friction and wear. in) Lecture 10 - Design Considerations for Hydrodynamic Lubrication Systems 1x Search within video (e. in NPTEL IITm NPTEL IITm Lecture 26 - Thermo Hydrodynamic LubricationLecture 26 - Thermo Hydrodynamic Lubrication Home NPTEL IITm NPTEL IITm Effective full film (hydrodynamic) lubrication can be achieved by continously feeding lubricant (as pressure greater than ambient pressure) through oil groove arrangement as shown in Fig. 27. The salient features of this type of motion can be understood from a study of slipper bearing (Fig. in) Micro fluidics by Prof. in Question 8: In hydrodynamic lubrication the major source of friction is A. Bearings operating in this regime have extensive metal-to-metal contact and partial hydrodynamic lubrication. May 6, 2020 · Classical lubrication theory naturally assumes that a lubricating oil is a Newtonian fluid with a fixed viscosity, and that the bearings are elastic solids, which might bend under oil pressure or Lecture 14 - Hydrodynamic LubricationLecture 14 - Hydrodynamic Lubrication HomePrevious Under these unfavorable conditions, hydrodynamic pressure developed is inadequate to support the load and they operate under either mixed-film or boundary lubricated conditions as depicted in the Stribeck curve shown in Fig. txt) or read online for free. For more details on NPTEL visit http://nptel. In hydrostatic lubrication external pressure is supplied to However, there is very short span of EHL regime compare to hydrodynamic and mixed lubrication, therefore exact knowledge of operating conditions (which is often very difficult) is a must for EHL design. Here, we combine elastic NPTEL IITm VDOM Modeling systems as hydrostatic, squeeze film and elasto-hydrodynamic lubrication will be studied as infinite and later finite structures. The slipper moves with a constant velocity U past the bearing plate. This slipper face The question comes, how lubrication really helps? It was earlier mentioned it reduces the friction it reduces the wear, but, in addition to that there are couple of more advantages of lubrication. 15M subscribers Subscribed Modeling systems as hydrostatic, squeeze film and elasto-hydrodynamic lubrication will be studied as infinite and later finite structures. Nov 2, 2015 · mod-05 lec-05 Capillary Fluid (incompressible) Flow and Hydrodynamic Lubrication nptelhrd 2. Question 17: In hydrodynamic lubrication minimum film thickness (hmin), a critical design criterion, is a function of : Subscribed 92 7. in Mar 1, 2013 · This lecture from NPTel, Indian Institute of Technology, discusses the principles and applications of journal bearings. May 6, 2020 · The development of EHL theory from its tentative beginnings is outlined, with an account of how Ertel explained its relation to Hertz contact theory. This slipper face Tribology by Dr. For a vast majority of the surfaces encountered in nature Hydrodynamic Lubrication In subject area: Materials Science Hydrodynamic lubrication (HL) is defined as a lubrication method where a thick fluid film prevents direct contact between friction-coupled elements, enabling them to operate without measurable wear over extended periods. in) Theory of Hydrodynamic Lubrication Thin film of oil, confined between the interspace of moving parts, may acquire high pressures up to 100 MPa which is capable of supporting load and reducing friction. The problems caused by the failure of the early numerical analysts to understand that the film thickness depends on only two variables are emphasised, and answers of the form H = F ( P , S ) given. Introduction The lubrication regime that occurs due to the elastic deformation of the lubricated contacts is the elastohydrodynamic lubrication regime. Basic Components, Symbols and Circuits Incompressible Fluids - Some Fundamental Properties Incompressible Fluid Flow related to Fluid Drive Capillary Fluid (incompressible) Flow and Hydrodynamic Lubrication Basis for Calculating Hydraulic Systems Different types of Valves - Features and Operations - I Definition of Hydrodynamic Lubrication (HL) Hydrodynamic lubrication is a term that defines a situation in which two rubbing surfaces are separated by a thin film of a lubricant. NPTEL IITm NPTEL IITm Tribology by Dr. Modeling systems as hydrostatic squeeze film and Elasto-hydrodynamic lubrication will be studied as infinite and later Lecture No. in) Modeling systems as hydrostatic, squeeze film and elasto-hydrodynamic lubrication will be studied as infinite and later finite structures. G. graphite) is preferable choice. in Access NPTEL Online IIT Kanpur for advanced courses and resources in engineering, science, and technology. Maiti of IIT Kharagpur. 2). 8K views 4 years ago Viscous Fluid Flow Viscous Fluid Flow Course URL: https://onlinecourses. Shearing of lubricant film. Tribology by Dr. C. in The video is first part of topic "Mechanism of lubrication" and it includes mechanism of hydrodynamic lubrication also known as thick film lubrication in detail. g: "acoustic", "hydraulics" or "friction") Speech Recogniser Status: Not Recognising Search and Play Video / Home Previous Next Lecture No. Fluid film lubrication is a generic term used for full film lubrication, in which solids surfaces are completely separated by fluid and wear is negligible. Today’s topic is thermo hydrodynamic lubrication. The journal bearing (Fig. . Harish Hirani, Department of Mechanical Engineering, IIT Delhi. in Viscous fluid flow covers the fundamentals of fluid mechanics from an advanced point of view. iitm. Nov 11, 2012 · Tribology by Dr. in Lecture 10 - Wear Analysis Lecture 11 - Lubrication and Lubricants Lecture 12 - Boundary Lubrication Lecture 13 - Lubrication Mechanisms Lecture 14 - Hydrodynamic Lubrication Lecture 15 - Lubricant Classifications Lecture 16 - Solid and Semi Solid Lubricants Lecture 17 - Liquid Lubricants Lecture 18 - Lubricant Additives Lecture 19 - Fluid Film Many times using only classical hydrodynamic lubrication theory predicts a negligible fluid film in contacts such as exist in rolling element bearings and gears, but on considering the influence of pressure on both elastic deformation and lubricant viscosity, a significant thickness becomes possible. ac. As the name indicates we are going to combine thermal effects with hydrodynamic effects and find out the pressure distribution based on that. In previous we have studied elasto hydrodynamic lubrication. Since a finite time is required to squeeze the viscous Lecture 10 - Wear Analysis Lecture 11 - Lubrication and Lubricants Lecture 12 - Boundary Lubrication Lecture 13 - Lubrication Mechanisms Lecture 14 - Hydrodynamic Lubrication Lecture 15 - Lubricant Classifications Lecture 16 - Solid and Semi Solid Lubricants Lecture 17 - Liquid Lubricants Lecture 18 - Lubricant Additives Lecture 19 - Fluid Film Modeling systems as hydrostatic, squeeze film and elasto-hydrodynamic lubrication will be studied as infinite and later finite structures. Modeling systems as hydrostatic, squeeze film and elasto-hydrodynamic lubrication will be studied as infinite and later Lecture -07 Lubrication regimes and film thickness calculations Lecture -08 Mixed Lubrication Lecture -09 Hydrodynamic lubrication theory Week 4: Data-Enabled Tribological approaches Lecture -10 Design considerations for hydrodynamic lubrication systems Four Types of Lubricant Regimes | Boundary | Mixed | Hydrodynamic | Elasto hydrodynamic Lubrication What are the main differences between grease and oil? Michell thrust bearing, named after A. For more details on NPTEL visit http://nptel. in) Nov 11, 2012 · Tribology by Dr. S. 87. Film means an exceedingly thin layer or a thin covering. Question 17: In hydrodynamic lubrication minimum film thickness (hmin), a critical design criterion, is a function of : Nov 11, 2012 · Tribology by Dr. Liquid lubrication is more common compared to gaseous lubrication. Chakraborty,Department of Mechanical Engineering,IIT Kharagpur. This lubrication regime is important for all lubrication regimes to understand because of its application in various mechanical components such as roller bearings, cam-tappet system, flexible seals, and bio-medical applications of human This course will cover the derivation of Navier-Stokes equations, exact solutions for simplified configurations, creeping flows , Stokes’s first and second problems, laminar boundary layers, wall-bounded and free-shear boundaries and hydrodynamic stability with an introduction to turbulence. Gas (air) lubricated and rolling contact type motions with deformation at contact will be studied as special systems. This type of lubrication is termed as Squeeze Film Lubrication Mechanism. 01/12/2017 NPTEL :: Mechanical Engineering - Tribology Module 5 : Fluid Film Lubrication Fluid Mechanics Concepts Fluid is defined as a substance that easily moves and changes its relative position without a separation from the bulk mass. nmpii jllghx grrq2af 0mh4x hg0uz x3ych hrmgzm ivc83 wig15o 7efkt