An adjoint preprocess for an adjoint-based turbomachinery design process is described. The resulting process is compared to a previously established adjoint process based on three-dimensional adjoint solutions and deformed meshes. Within the new process, the calculation of sensitivities is performed using shape sensitivities and surface displacements, where the design parameters are computer-ai...

This paper presents an adjoint method for the optimum shape design of unsteady three-dimensional viscous flows. The goal is to develop a set of discrete unsteady adjoint equations and the corresponding boundary condition for the non-linear frequency domain method. First, this paper presents the complete formulation of the time dependent optimal design problem. Second, we present the non-linear ...

This paper presents an adjoint method for the optimal control of unsteady flows. The goal is to develop the continuous and discrete unsteady adjoint equations and their corresponding boundary conditions for the time accurate method. First, this paper presents the complete formulation of the time dependent optimal design problem. Second, we present the time accurate unsteady continuous and discr...

In this paper we analyze the consistency properties of discrete adjoints of linear multistep methods. Discrete adjoints are very popular in optimization and control since they can be constructed automatically by reverse mode automatic differentiation. The consistency analysis reveals that the discrete linear multistep adjoints are, in general, inconsistent approximations of the adjoint ODE solu...

Adjoint sensitivity analysis is used to study the New York Bight circulation for three idealized situations: an unforced buoyant river plume, and upwelling and downwelling wind forcing. A derivation of adjoint sensitivity is presented that clarifies how the method simultaneously addresses initial, boundary, and forcing sensitivities. Considerations of interpretation and appropriate definitions ...

This paper presents an adjoint method for the calculation of non-collocated sensitivities in supersonic flow. The goal is to develop a set of discrete adjoint equations and their corresponding boundary conditions in order to quantify the influence of geometry modifications on the pressure distribution at an arbitrary location within the domain of interest. First, this paper presents the complet...

This paper presents an adjoint method for the calculation of remote sensitivities in supersonic flow. The goal is to develop a set of adjoint equations and their corresponding boundary conditions in order to quantify the influence of geometry modifications on the pressure distribution at an arbitrary location within the domain of interest. First, this paper presents the formulation and discreti...

Phase-retrieval from measured phaseless field data is of interest for various applications including electromagnetic dosimetry, electromagnetic compatibility investigations, near-field to far-field transformations and antenna diagnostics. In this study two phaseretrieval methods, namely the adjoint field method and the phase angle gradient method, are compared using 3D numerical test cases. The...

This paper presents a discrete adjoint method for a broad class of time-dependent optimization problems. The time-dependent adjoint equations are derived in terms of the discrete residual of an arbitrary finite volume scheme which approximates unsteady conservation law equations. Although only the 2-D unsteady Euler equations are considered in the present analysis, this time-dependent adjoint m...

One-dimensional δ ′ -function potential is discussed in the framework of Green’s function formalism without invoking perturbation expansion. It is shown that the energy-dependent Green’s function for this case is crucially dependent on the boundary conditions which are provided by self-adjoint extension method. The most general Green’s function which contains four real self-adjoint extension pa...