Aerospace Science and Technology
Hossein Shadmehr; Sajad Ghasemloo; Hamid Parhizkar
Abstract
In this article, the idea of building a supersonic wind tunnel has been provided that uses a high-pressure steam flow of a combined cycle power plant. This has been investigated by CFD method. Using the plant's output steam as a high-pressure source can be used in the ejector to create supersonic airflow ...
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In this article, the idea of building a supersonic wind tunnel has been provided that uses a high-pressure steam flow of a combined cycle power plant. This has been investigated by CFD method. Using the plant's output steam as a high-pressure source can be used in the ejector to create supersonic airflow in the test chamber. For this purpose, first, the numerical model has been validated in comparison with the previous numerical and experimental results. The numerical model used is the viscous compressible flow, which is performed by the k-ω-SST turbulent modeling of the turbulence model. All calculations are performed in ANSYS-FLUENT software. After validating the numerical process, various geometries have been proposed to achieve the ultrasonic secondary flow and each structure is examined numerically separately in a range of functional conditions. Through trial and error method and looking at the achievements of previous research, in a very long process and by testing several different structures, a suitable structure has been obtained to achieve the supersonic testing chamber. This structure has been studied parametrically under different functional conditions. It has been shown that the proposed structure can generate an ultrasonic flow in an acceptable range of power plant steam flow and pressure. This structure has been proposed for the first time in the literature in this field, and in no previous research has such a structure been proposed. Access to the ultrasonic secondary flow is also a major innovation of this research.
A. R. Jahangirian; M. Ebrahimi
Volume 11, Issue 1 , June 2017
Abstract
An efficient method for scattering Genetic Algorithm (GA) individuals in the design space is proposed to accelerate airfoil shape optimization. The method used here is based on the variation of the mutation rate for each gene of the chromosomes by taking feedback from the current population. An adaptive ...
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An efficient method for scattering Genetic Algorithm (GA) individuals in the design space is proposed to accelerate airfoil shape optimization. The method used here is based on the variation of the mutation rate for each gene of the chromosomes by taking feedback from the current population. An adaptive method for airfoil shape parameterization is also applied and its impact on the optimum design and convergence of the optimization process isinvestigated. In order to demonstrate the efficiency of the proposed method, a geometric inverse design using Genetic Algorithm is carried out and the capability of the method for producing airfoil shapes is assessed. The performance of the method is further evaluated by an aerodynamic shape optimization. Results indicate the merits of the method in increasing the maximum objective value about7percent as well as decreasing the total computational time up to28 percent.