Source: https://www.researchgate.net/profile/Florin-Ilinca/publication/45428364_A_Continuous_Shape_Sensitivity_Equation_Method_for_Unsteady_Laminar_Flows/links/09e4150b64c2e6d31a000000/A-Continuous-Shape-Sensitivity-Equation-Method-for-Unsteady-Laminar-Flows.pdf