Parallel Evaluation of Quantum Algorithms for Computational Fluid Dynamics

The development and evaluation of quantum computing algorithms for computational fluid dynamics is described along with a detailed analysis of the parallel performance of a quantum computer simulator developed as part of the present work. The quantum computer simulator is used in the evaluation of the quantum algorithms on a conventional parallel computer, and is applied to quantum lattice-based algorithms as well as the Poisson equation. A key result is a demonstration of how the Poisson equation can be solved effeciently on a quantum computer, while its use within a larger algorithm representing a full CFD solver poses a number of signifi- cant challenges

Coupled flight dynamics and CFD - demonstration for helicopters in shipborne environment

The development of high-performance computing and computational fluid dynamics methods have evolved to the point where it is possible to simulate complete helicopter configurations with good accuracy. Computational fluid dynamics methods have also been applied to problems such as rotor/fuselage and main/tail rotor interactions, performance studies in hover and forward flight, rotor design, and so on. The GOAHEAD project is a good example of a coordinated effort to validate computational fluid dynamics for complex helicopter configurations. Nevertheless, current efforts are limited to steady flight and focus mainly on expanding the edges of the flight envelope. The present work tackles the problem of simulating manoeuvring flight in a computational fluid dynamics environment by integrating a moving grid method and the helicopter flight mechanics solver with computational fluid dynamics. After a discussion of previous works carried out on the subject and a description of the methods used, validation of the computational fluid dynamics for ship airwake flow and rotorcraft flight at low advance ratio are presented. Finally, the results obtained for manoeuvring flight cases are presented and discussed

Computational fluid dynamics challenges for hybrid air vehicle applications

This paper begins by comparing turbulence models for the prediction of hybrid air vehicle (HAV) flows. A 6 : 1 prolate spheroid is employed for validation of the computational fluid dynamics (CFD) method. An analysis of turbulent quantities is presented and the Shear Stress Transport (SST) k-ω model is compared against a k-ω Explicit Algebraic Stress model (EASM) within the unsteady Reynolds-Averaged Navier-Stokes (RANS) framework. Further comparisons involve Scale Adaptative Simulation models and a local transition transport model. The results show that the flow around the vehicle at low pitch angles is sensitive to transition effects. At high pitch angles, the vortices generated on the suction side provide substantial lift augmentation and are better resolved by EASMs. The validated CFD method is employed for the flow around a shape similar to the Airlander aircraft of Hybrid Air Vehicles Ltd. The sensitivity of the transition location to the Reynolds number is demonstrated and the role of each vehicle£s component is analyzed. It was found that the ¦ns contributed the most to increase the lift and drag

Comparison of discrete velocity method and gas-kinetic method for binary gas mixtures

The formulation of computationally efficient methods describing gas mixtures at kinetic level suitable for demanding aerospace applications presents significant challenges. This work presents a gas-kinetic scheme for binary gas mixtures in which the kinetic model is capable of recovering, in the continuum limit, the correct heat transfer, mixture viscosity, and species diffusion. The model accounts for separate species-mean velocity such that the species diffusion and velocity drift are accurately represented. The main goal is to derive a numerically efficient gas kinetic scheme (GKS) method that has the ability to accurately model species diffusion and velocity drift, such that two-species Navier–Stokes equations are recovered with the correct Prandtl number. The paper compares the solutions of the underlying kinetic model obtained using the GKS method and the discrete velocity method. The limitations of the GKS for different flows and different levels of thermodynamic nonequilibrium are examined. Supersonic flows with varying species mass ratios, concentrations, and Knudsen number are investigated. For the cases considered a good agreement is observed, showing that the developed GKS method provides a valuable approach for modeling these challenging flows. Also, the reduction in required CPU time for the GKS relative to discrete velocity method is shown to be significant

Simulation of flow around oscillating rotor blade section with aeroelastic flap

Flows around rotor blade sections equipped with active flaps with a degree of freedom in the flap deflection angle are considered in this paper. Results for oscillating flaps are presented. The resultant flap motion was found to couple with the unsteady air loads for cases of blade section in oscillatory translation

CFD and aeroelastic analysis of the MEXICO wind turbine

This paper presents an aerodynamic and aeroelastic analysis of the MEXICO wind turbine, using the compressible HMB solver of Liverpool. The aeroelasticity of the blade, as well as the effect of a low-Mach scheme were studied for the zero-yaw 15m/s wind case and steady- state computations. The wake developed behind the rotor was also extracted and compared with the experimental data, using the compressible solver and a low-Mach scheme. It was found that the loads were not sensitive to the Mach number effects, although the low-Mach scheme improved the wake predictions. The sensitivity of the results to the blade structural properties was also highlighted

Assessment of Implicit Implementation of the AUSM+ Method and the SST Model for Viscous High Speed Flow

No abstract available

Shock interactions in continuum and rarefied conditions employing a novel gas-kinetic scheme

Shock interactions can have a significant impact on heating rates and aerodynamic performance of hypersonic vehicles. The study presents different shock interactions in partially rarefied hypersonic flows predicted employing a recently developed gas-kinetic scheme for diatomic gases with rotational degrees of freedom. The new gas-kinetic schemes will be presented along with shock/wave boundary interactions as well as Edney Type IV shock–shock interactions. Various levels of rarefaction have been considered to highlight the effect of thermal relaxation between the translational and rotational modes. In addition, for the Edney test case, the imposed wall temperature on the shock-generating wedge and the cylinder surface has been varied, to evaluate the importance of the boundary layer thickness in the interaction region

CFD Analysis of Rotor-Fuselage Aerodynamics based on a Sliding Mesh Algorithm

Rotor-fuselage interaction is central to the design and performance analysis of helicopters. However, regardless of its significance this problem is not well-studied and few CFD works have so far been published. In this paper, a method is put forward to allow CFD computations of rotor-fuselage problems using a sliding mesh to interface the rotor and fuselage regions. A sliding plane forms a boundary between a CFD mesh around the fuselage and a rotor-fixed CFD mesh which has to be rotated to account for the motion of the rotor blades. CFD meshes adjacent to a sliding plane do not necessarily have matching nodes or even the same number of cell-faces. This poses a problem of interpolation between CFD meshes and, in addition, the employed algorithms should have small CPU overhead. The properties of this method are assessed and validation results are presented for several flow case