CFD Brief History

Although the study of fluid mechanics is centuries old most of the evolution of CFD took place throughout the twentieth century. By the start of the twentieth century all of the basic governing equations were consolidated. Closed form analytical solution for simple problems were derived putting aside the large set of problems of practical significance that are not suitable for analytical solution. Before the 1950's the main focus was on developing a variety of approximated semi analytical techniques such as perturbation methods for viscous boundary layer calculations, a method of characteristics for compressible flow calculations alongside the numerical solution development. By the mid-century the Finite difference based numerical methods were developed. However, the numerical algorithms until the fifties provided a solution to the single partial differential equations limited by the computation power. With the advent of digital computers the development of numerical simulation was put on an accelerated path. During the fifties and sixties significant developments were made on solution of inviscid compressible flows.

The seventies largely focused on inviscid flows over geometries like airfoils, wings and wing-body combinations. During the eighties intense efforts were made on algorithms for solution of Euler equations which include rotational flows but still inviscid. Research on grid generation was invested in the late eighties which presented a challenge in generating suitable grids for the computational domain of complex geometries. During the late eighties the transonic flow computations with viscous compressible flow over airfoils was made possible. This resulted in designing the super critical airfoils computationally with reduced wave drag. For the first time one could move away from the catalogued airfoil shapes to custom-designed airfoils to suite design end.

In the nineties the power of parallel computing paved the way for turbulence modeling in the flow. Turbulence was incorporated using turbulence modeling techniques such as Reynolds-averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) along with Direct Numerical Simulation (DNS) without any modeling. This period marked the beginning of an era of commercial software capable of impressive visualization of vast numerical data generated by the CFD simulation of flow fields.