Sensitivities for a Single Drop Simulation.




In process engineering, a single drop is investigated to better understand its physical and chemical behavior. Laboratory experiments using the Nuclear Magnetic Resonance (NMR) technology are prepared by numerical simulations aiming at finding a suitable geometry of the measuring cell. In the underlying numerical optimization problem, derivatives of the flow field around a single drop with respect to geometric parameters are needed. Rather than using numerical differentiation based on divided differencing, a technique called automatic differentiation is used to compute truncation-error free derivative values. It is shown that automatic differentiation is comparable to numerical differentiation in terms of CPU time but eliminates potential problems in accuracy encountered when using numerical differentiation.