Splines are used extensively at Boeing and throughout much of the industrial world. Cubic splines are used in the numerical solution of differential equations which arises in several complex systems such as physics, chemistry, fluid mechanics, viscoelasticity, signal processing, mathematical biology, bioengineering and various applications in many branches of science and engineering. Spline solution is developed for solving a system of boundary value problems. Cubic splines are applied in image interpolation and digital filtering. To know the behaviour of fluids in motion, the physical phenomena are observed, the fundamental laws are verified, the thermodynamical properties are examined and the characteristic mathematical formulations are made. Thus, the problems of fluid flow are analyzed and understood.