Relationship between a model and Similitude

Relationship between a model and proportion For a model, similitude is achieved when testing conditions argon created such that the test results atomic number 18 applicable to the real design. There argon some criteria that are needed to achieve similitude 1 . Geometric similarity The model is the alike(p) shape as the application (they are usu onlyy scaled). 2. Kinematic similarity peregrine turn tail of both the model and real application must sustain similar time rates of change motions. (Fluid streamlines are similar). 3.Dynamic similarity Ratios of all forces acting on orresponding fluid particles and boundary surfaces in the two systems are constant.The application is analyzed in order to satisfy the conditions 1 . every last(predicate) parameters required to describe the system are Identified using principles from continuum mechanics. 2. dimensional analysis is used to express the system with as few autonomous variables and as many dimensionless parameters as poss ible. 3. The values of the dimensionless parameters are held to be the said(prenominal) for both the scale model and application.This can be done because they are dimensionless and will ensure dynamic similitude between the model and the application. The resulting equations are used to derive scaling laws which dictate model testing conditions. However, it is oftentimes impossible to achieve strict similitude during a model test. The greater the departure from the applications operating conditions, the more difficult achieving similitude is. Similitude is a term used widely in fracture mechanics relating to the poke out life approach.Under given loading onditions the wear out damage in an unnotched specimen is comparable to that of a notched specimen. Similitude suggests that the component fatigue life of the two objects will also be similar. One physical exertion that we can give here Is the. Pipe friction apparatus has been designed for students to measure pipe friction loss es for stratified and miffed descends. For laminar flow study, an elevated head tank Is used for water supply, whilst for turbulent flow the supply is from the Hydraulics Bench using oses with rapid achieve hose coupling.Students may control the flow rate of water by adjusting the flow regulator valve. The test section is connected to manometers via pressure tapplngs. The intent (objectives) doing this experiment are Measurement of the pressure loss for laminar flow Measurement of the pressure loss for turbulent flow Determination of the scathing Reynolds number Measurements using a tube manometer Measurements using a mercury U tube manometer Reynolds number in pipe frictionPressure drops seen for fully develop flow of fluids through pipes can be predicted 1 OF2 uslng tne Moody Olagram wnlcn plots tne Darcy-welsoacn Trlctlon Tactor T against Reynolds number Re and relative roughness. The draw clearly shows the laminar, transition, and turbulent flow regimes as Reynolds num ber increases. The nature of pipe flow is strongly certified on whether the flow is laminar or turbulent. using the Moody diagram which plots the Darcy-Weisbach friction factor f against Reynolds number Re and relative roughness . The diagram clearly shows the laminar,