aMunish Gupta, bGulshan Sachdeva.
cKinshuk Kalia, dAnkur Puri.
a, b: Lecturer, Department of Mechanical Engineering.
c, d: U.G students, Department of Mechanical Engineering. Guru Jambheshwar University of Science & Technology, Hisar, Haryana.
With so much development in numerical methods, the field of computational mechanics has become sufficiently mature to collect & summarize it in a portable format. It has been the intention to provide the community with a systematic, established as well as recently developed computational methods, covering computational mathematics, computer sciences, various branches of fluid mechanics & all the available discretization methods.
Introduction to CFD
Breaking down the CFD into 2 parts, Computational – having to do with mathematics, modeling; Fluid Dynamics – the study of the things that flows. This is CFD- a computational technology that enables us to study the dynamics of things that flow. Using CFD, we can build a computational model that represents a system or device that we want to study. Then we apply the fluid flow physics & chemistry to this virtual prototype & the software will output a prediction of fluid dynamics & related physical phenomenon. Therefore, CFD is a sophisticated computationally based design & analysis technique. CFD software gives us the power to simulate flows of gases & liquids, heat & mass transfer, moving bodies, multiphase physics, chemical reaction, fluid structure interaction & Acoustics through computer modeling. Using CFD software, we can build a ‘virtual prototype’ of the system or device that we wish to analyze & then apply real-world physics & chemistry to the model, & the software will provide us with images & data, which predict the performance of that design. In simple words CFD can be stated as the analysis of the system involving fluid flow, heat transfer & associated phenomenon by means of computer based solution.
Why do we study CFD?
CFD is widely used in industries, because it used as a research tool by which we check the stability of the model that we want to build by simulating the flow around the body. The CFD techniques are also used as a research tool. CFD has developed to a point where the complete 3-D flow field over the body can be computed with accuracy & reliability. Ground test facilities; unfortunately do not exist in all velocity regimes covered by a body which is moving with a very high velocity. Also the money involved in the wind tunnel testing is quite high. In today’s world, knowledge of CFD is a must for those who will work in the field of fluid mechanics, chemical engineering, heat transfer & even machine design. CFD is attractive to industry since it is more cost-effective than physical testing. However, one must note that complex flow simulations are challenging and error-prone and it takes a lot of engineering expertise to obtain validated solutions.
CFD as a research tool
CFD results are highly analogous with wind tunnel test results – they both represent sets of data for given flow configurations at different Mach numbers, Reynolds numbers etc. CFD allows us to study in detail the physical difference between the laminar & turbulent flows, all other parameters being equal, in a manner which is impossible to obtain in an actual laboratory experiment.
What is CFD?
The physical aspects of any fluid flow are governed by 3 fundamental principles: Mass is conserved, Newton’s second law (Conservation of momentum), Energy is conserved. These physical principles are applied to a model of the flow; this application results in equations which are mathematical statements of the particular physical principles involved, viz. the continuity, momentum & energy equations. The fundamental physical problems can be expressed in terms of basic mathematical...