Durbha V. Murthy

Semianalytical technique for sensitivity analysis of unsteady aerodynamic computations

A semianalytical approach is developed for the sensitivity analysis of linear unsteady aerodynamic loads. The semianalytical approach is easier to implement than the analytical approach. It is also computationally less expensive than the finite-difference approach when used with panel methods that require a large number of panels. The semianalytical approach is applied to an isolated airfoil in a two-dimensional flow and rotating propfan blades in three-dimensional flow

Application of a semianalytical technique for sensitivity analysis of unsteady aerodynamic computations

A semianalytical approach is developed for the sensitivity analysis of linear unsteady aerodynamic loads. The semianalytical approach is easier to implement than the analytical approach. It is also computationally less expensive than the finite difference approach when used with panel methods which require a large number of panels. The semianalytical approach is applied to an isolated airfoil in a two-dimensional flow and rotating propfan blades in three-dimensional flow. Sensitivity coefficients with respect to nonshape-dependent variables are shown for some cases.

Concurrent processing adaptation of aeroelastic analysis of propfans

Abstract This paper reports on a study involving the adaptation of an advanced aeroelastic analysis program to run concurrently on a shared memory multiple processor computer. The program uses a three-dimensional compressible unsteady aerodynamic model and blade normal modes to calculate aeroelastic stability and response of propfan blades. The identification of the computational parallelism within the sequential code and the scheduling of the concurrent subtasks to minimize processor idle time are discussed. Processor idle time in the calculation of the unsteady aerodynamic coefficients was reduced by the simple strategy of appropriately ordering the computations. Speedup and efficiency results are presented for the calculation of the matched flutter point of an experimental propfan model. The results show that efficiencies above 70% can be obtained using the present implementation with seven procesors. The parallel computational strategy described here is also applicable to other aeroelastic analysis procedures based on panel methods.

Parallel computation of aerodynamic influence coefficients for aeroelastic analysis on a transputer network

Abstract Aeroelastic analysis is multi-disciplinary and computationally expensive. Hence, it can greatly benefit from parallel processing. As part of an effort to develop an aeroelastic analysis capability on a distributed-memory transputer network, a parallel algorithm for the computation of aerodynamic influence coefficients is implemented on a network of 32 transputers. The aerodynamic influence coefficients are calculated using a three-dimensional unsteady aerodynamic model and a panel discretization. Efficiencies up to 85% are demonstrated using 32 processors. The effects of subtask ordering, problem size and network topology are presented. A comparison to results on a shared-memory computer indicates that higher speedup is achieved on the distributed-memory system.