Showing posts from June, 2021

Basic Types, shapes, Grid and Geometry Mesh used in CFD

Basics of Meshing in CFD Discretizing a domain into small elements or cells is known as meshing. Meshing is a very important part of numerical analysis. If the number of cells in a meshed domain are high the accuracy of analysis will be greater. Mesh is kept fine in the areas where capturing the physics of phenomenon is important. Mesh independence is one of the most important step in meshing. Mesh Independence is achieved by refining the mesh till the value of required variable becomes constant. Mesh refining requires high computational capabilities. Mesh can be classified into different types based on the uniformity and shape. Definitions of some elementary terms of meshing are given below (D. J. 1996). Node: Point where two or more edges meet. Edge: Boundary of a face Face: Boundary of a cell Cell: Control volume into which the domain is discretized. Zone: Grouping of nodes faces and cells Material data and source terms are assigned to cell zone whereas boundary conditions are appli

CFD analysis of Tesla Turbine

CFD Studies of Tesla Turbine In Jung (2014) work the flow rate was chosen as 0.0001. Iteration of disc outer radius and fluid angular velocity was done to find the volumetric flow rate for single disc spacing. In order to obtain the overall volumetric flow rate, the disk configuration was multiplied by the overall number of discs, giving appropriate efficiency and torque values. There was an iteration of head and flow speeds. Via the nozzle, fluid makes its way and is guided between the discs. The fluid hits the disc at an inclination nearly tangentially to the outside of the rotor, locating the jet's absolute and radial velocity. It measured the torque and generated power. Jung (2014) worked on a CFD model of a Tesla turbine based on the design parameters mentioned above. In Solidworks2013, 2 domains were formed. The revolving domain comprised of a rotor assembly and the stationary domain composed of a simplistic nozzle in the outer casing. Figure below illustrates the layout of t

Practical Designs, Numerical, Analytical and Experimental Studies of Tesla Turbine

Numerical and Analytical studies of Tesla Turbine Many analytical and numerical attempts by various investigators were made during mid-nineteenth century to describe behavior of turbulent and laminar flow areas for flow between the tesla turbine’s disks. At times, computational tool capability was very limited that is why most of their studies had to rely on simple flow assumptions. Prof. W. Rice is one of the investigators who by employing different set of formulations has made his great efforts in describing and making a mathematical model of characteristics of operation and summation of parameters of multi-disk turbo machinery. He published an article in 1963 for the selection of quantity of disks of air-based friction compressors & pumps based on an incompressible and steady state flow in single inter-disk space by the determination of surface force and solution of the respective motion equations in tangential and radial coordinates. This study established the higher limit on p

Advantages and Disadvantages of Tesla Turbine

Advantages of Tesla Turbine There are numerous technological and operational advantages of the Tesla turbine. Some of them are listed below.  • Extreme simplicity, reliability and dependability  • Better stability owing to the uniform distribution of the mass of the rotor on the rotation axis • Owing to its compact scale and low periphery speeds, small mechanical stress are produced in the turbine. • Only radial and tangential fluid forces act on the rotating portion of the turbine, and it faces no axial load. • Within the housing the internal static pressure is very little, so heavy cast housing is not needed to ensure the structural rigidity(AndrĂ©s, 2004)  • As flow does not impinge directly on the surface of disk and there is a marginal static pressure differential inside the disk-casing assembly among the disks sides, the rotors are not much vulnerable to undergo cavitation (disks). • Exotic fluid handling ability, e.g., high viscosity fluids, mixtures of gas and liqu

Geometry, Working and Application of Tesla Turbine

A bladeless turbine called Tesla turbine comprised of a sequence of Nozzle discs from which gas or liquid flows to the disc edge. Related to fluid properties of viscosity and adhesion, momentum transformation among fluid and disc occurs. Discs and washers are mounted on a sleeve with individual discs, fixed at the top, and nuts are used to keep dense top plates intact. There is a void in the sleeve which fits tightly onto the shaft. To connect with exhaust ports founded on the edge of the casing, holes are carved out across the middle of the discs. Therefore, a multi-disk tesla turbine is known as a shear force or secondary flow turbo equipment that operates with compressible and incompressible fluid. Fluid arrives radially then through the channels exits axially. The benefits of the Tesla turbine are ease of development, flexibility and low servicing. Vapor or water can be the fluid used. Owing to the absence of vanes, it is untouched by sediment erosion. Low performance is a problem

Understand the material hardness and effect of carbon content and heat treatment on hardness

Aim “Understand the material hardness and effect of carbon content and heat treatment on hardness” Aim of this lab work is to understand the material hardness of different materials and effect of carbon content present in material on material hardness and effect of heat treatment of material on material hardness. Objectives In order to achieve the aim of this lab work the following mention objectives have to be completed in said sequence 1.      Develop a comprehensive understanding of methods used for measuring material hardness 2.      Develop a comprehensive understanding of effect of carbon percentage on material hardness 3.      Develop a comprehensive understanding of effect of heat treatment on material hardness 4.      Perform hardness test to measure material hardness 5.      Perform hardness test after increasing carbon content 6.      Perform hardness test after heat treatment of material 7.      Develop a comprehensive conclusion about work Theory Hardness Material hardness

Lab Report Bending of a simply supported beam

Aim “To study deflection in a simply supported beam” This lab is aimed to study the behavior of simply supported beam under the action of a point load. Objectives The goal of comprehending the simply supported beam in an effective way can be achieved through step by step approach. It is very important that we follow the below given steps in the same order as they are listed. Grasp the basic design of the beam and its working Strain produced in the beam under the action of load Perform experiment to study the strain produced in the beam and using strain gauge to measure strain Introduction Beam Beam is one of the simplest but very important component of every structure or building. A simply supported beam has supports at both ends. It features roller support at one end and pinned support at the other. These beams can undergo both bending and shear stress. Therefore, these beams should be designed such that they are able to bear shear and bending stress applied on them. Bending stresses

Cutting force monitoring using strain guage

Force monitoring An electric circuit, that is fit for estimating the exceptionally little changes in resistance comparing to strain. This circuitry is utilized to quantify the strain with fortified opposition strain gauges. Typically, four strain gauge components are electrically associated with structure a Wheatstone bridge circuitry.  A Wheatstone bridge is a separated bridge circuit utilized for the estimation of static or dynamic electrical opposition. The yield voltage of the Wheatstone bridge circuit is as milli volts (mv) yield per volt input. The Wheatstone circuit is likewise appropriate for temperature compensation. The numerical representation of the Wheatstone bridge, if R1, R2, R3, and R4 are equivalent, and a voltage, Vin , is applied between focuses A and C, at that point the yield between focuses B and D will show no expected distinction. Notwithstanding if R4 is changed to some esteem which doesn't rise to R1, R2, and R3, the bridge will become unequal and a voltag

Explain single point cutting tool geometry, angles and materials properties

Tool Geometry Cutting Tool Geometry 1. Shank: It is the body of the tool. It includes the part of tool which is inserted in tool post to hold the tool in machine. In simple words, it joins the handle and operational end. 2. Flank: The surface of the tool adjacent to and facing work piece is called flank. A tool have two types of flanks i.e. major and minor flank. Major flank is also called side flank whereas minor flank is also called end flank. Minor flank is the end face of the tool which is facing the work piece while major flank is the adjacent surface to the minor flank. 3. Base: The opposite side of shank with respect to the top side of tool is known as base. 4. Face: Rake surface is also called tool face. This allows the chips of work piece to flow over the tool.  5. Cutting edge: The edge of tool that removes material by coming into contact with work piece is known as cutting edge. A tool have two cutting edges.  i. Side cutting edge: Top edge of side flank is knows as side c