Dr Narasimha has made significant contribution in the broad field of fluid mechanics. In particular, his studies relating to turbulence, boundary layers and rarefied gas dynamics have opened new horizons and helped in obtaining a better understanding of these phenomena. His main forte is to extract simple physical models from complex engineering problems and apply sophisticated mathematical tools to obtain a better understanding of them. Typical examples of his versatility are his studies related to satellite vehicles applying rarefied gas dynamics theories, statistical analysis of the relationship between performance and maintenance of aircraft, studies related to flow-induced oscillations in nuclear reactor Calandria, and the structure of turbulent and transitional fluid flows.