Thank you for reading numerical heat transfer and fluid flow. Maybe you have knowledge that, people have search numerous times for their favorite books like this numerical heat transfer and fluid flow, but end up in infectious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they cope with some malicious virus inside their computer. numerical heat transfer and fluid flow is available in our digital library an online access to it is set as public so you can get it instantly. Our books collection spans in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Merely said, the numerical heat transfer and fluid flow is universally compatible with any devices to read.

Numerical Heat Transfer And Fluid Flow

This paper presents multipoint high-fidelity aerostructural optimizations of a long-range wide-body transonic transport aircraft configuration. The aerostructural analysis employs Euler computational fluid dynamics with a 2-million-cell mesh and a structural finite-element model with 300,000 degrees of freedom. The coupled adjoint sensitivity method is used to efficiently compute gradients, enabling the use of gradient-based optimization with respect to hundreds of aerodynamic shape and structural sizing variables. The NASA Common Research Model is used as the baseline configuration, together with a wing box structure that was designed for this study. Two design optimization problems are solved: one where takeoff gross weight is minimized, and another where fuel burn is minimized. Each optimization uses a multipoint formulation with five cruise conditions and two maneuver conditions. Each of the optimization problems have 476 design variables, including wing planform, airfoil shape, and structural thickne...

/pdf/multipoint-high-fidelity-aerostructural-optimization-of-a-58w2jsahxc.pdf

Multipoint High-Fidelity Aerostructural Optimization of a Transport Aircraft Configuration

Electric, hybrid, and turboelectric fixed-wing aircraft: A review of concepts, models, and design approaches

Aeroelastic systems achieve the best performance when the aerodynamic shape and structural sizing are optimized concurrently, but such an optimization is challenging when high-fidelity aerodynamic and structural models are required. This paper addresses this challenge through several significant improvements. Fully coupled Newton–Krylov methods are presented for the solution of aerostructural systems and for the corresponding adjoint systems. The coupled adjoint method presented can compute gradients with respect to thousands of multidisciplinary design variables accurately and efficiently. This is enabled by several improvements in the computation of the multidisciplinary terms in the coupled adjoint. The parallel scalability of the methods is demonstrated for a full aircraft configuration using an Euler computational fluid dynamics model with more than 8×106 state variables and a detailed structural finite element model of the wing with more than 1×106 degrees of freedom. The coupled Newton–Krylov metho...

/pdf/scalable-parallel-approach-for-high-fidelity-steady-state-1b4fa0680m.pdf

Scalable Parallel Approach for High-Fidelity Steady-State Aeroelastic Analysis and Adjoint Derivative Computations

Theory Of Wing Sections Including A Summary Of Airfoil Data

Ambitious targets to reduce emissions caused by aviation in the light of an expected ongoing rise of the air transport demand in the future drive the research of propulsion systems with lower CO2 emissions. Regional hybrid electric aircraft (HEA) powered by conventional gas turbines and battery powered electric motors are investigated to test hybrid propulsion operation strategies. Especially the role of the battery within environmentally friendly concepts with significantly reduced carbon footprint is analyzed. Thus, a new simulation approach for HEA is introduced. The main findings underline the importance of choosing the right power-to-energy-ratio of a battery according to the flight mission. The gravimetric energy and power density of the electric storages determine the technologically feasibility of hybrid concepts. Cost competitive HEA configurations are found, but do not promise the targeted CO2 emission savings, when the well-to-wheel system is regarded with its actual costs. Sensitivity studies are used to determine external levers that favor the profitability of HEA.

Conceptual Design of Operation Strategies for Hybrid Electric Aircraft

Development and implementation of an advanced, design-sensitive method for wing weight estimation

This paper presents the development of a quasi-three-dimensional aerodynamic solver, which provides accurate results for wing drag comparable to the higher-fidelity aerodynamic solvers at significantly lower computational costs. The proposed solver calculates the viscous wing drag using the combination of a two-dimensional airfoil analysis tool with a vortex lattice code. Validation results show that the results of the quasi-three-dimensional solver are in good agreement with higher-fidelity computational fluid dynamics solvers. The quasi-three-dimensional solver is used for a wing shape multidisciplinary design optimization. A multidisciplinary design optimization problem is formulated to design the wing shape of a typical passenger aircraft. The aircraft maximum takeoff weight is considered as the objective function. Two optimization algorithms, a local and a global optimum finder, are implemented in the multidisciplinary design optimization system. The optimization results indicate that the global opti...

Quasi-Three-Dimensional Aerodynamic Solver for Multidisciplinary Design Optimization of Lifting Surfaces

A surrogate-based multi-disciplinary design optimization framework modeling wing–propeller interaction

This paper presents a method for wing aerostructural analysis and optimization, which needs much lower computational costs, while computes the wing drag and structural deformation with a level of accuracy comparable to the higher fidelity CFD and FEM tools. A quasi-three-dimensional aerodynamic solver is developed and connected to a finite beam element model for wing aerostructural optimization. In a quasi-three-dimensional approach an inviscid incompressible vortex lattice method is coupled with a viscous compressible airfoil analysis code for drag prediction of a three dimensional wing. The accuracy of the proposed method for wing drag prediction is validated by comparing its results with the results of a higher fidelity CFD analysis. The wing structural deformation as well as the stress distribution in the wingbox structure is computed using a finite beam element model. The Newton method is used to solve the coupled system. The sensitivities of the outputs, for example the wing drag, with respect to the inputs, for example the wing geometry, is computed by a combined use of the coupled adjoint method, automatic differentiation and the chain rule of differentiation. A gradient based optimization is performed using the proposed tool for minimizing the fuel weight of an A320 class aircraft. The optimization resulted in more than 10 % reduction in the aircraft fuel weight by optimizing the wing planform and airfoils shape as well as the wing internal structure.

/pdf/coupled-adjoint-aerostructural-wing-optimization-using-quasi-18h5vjdn9f.pdf

Ali Elham

Papers

Conceptual Design of Operation Strategies for Hybrid Electric Aircraft

Development and implementation of an advanced, design-sensitive method for wing weight estimation

Quasi-Three-Dimensional Aerodynamic Solver for Multidisciplinary Design Optimization of Lifting Surfaces

A surrogate-based multi-disciplinary design optimization framework modeling wing–propeller interaction

Coupled adjoint aerostructural wing optimization using quasi-three-dimensional aerodynamic analysis