The Fast Simulation of Highly Flexible Flight Dynamics
Lead Research Organisation:
University of Glasgow
Department Name: School of Engineering
Abstract
A combined formulation of the finite element method and computational fluid dynamics could be used to simulate the flight dynamics of highly flexible aircraft, but this would result in a very computationally expensive problem which may require many hours to solve even with high performance computing resources.
The purpose of the proposed project is to reduce the computational cost of the analysis of combined flight dynamics and aeroelastics for highly flexible aircraft through the use of alternative, lower order methods.
The project would initially involve investigation into the state of the art low order structural dynamics and fluid dynamics methods. Based on the outcome of the literature review, methods would be chosen to investigate, extend and implement within a computer code.
The code will then be verified, most probably using data collected from a highly flexible model aircraft built by a team at the Institute of Aeronautical Technology in Brazil. It is likely that the code may become complex due to the need to be able to model a full model in comparison to a "toy" case. Once verified, the code will be compared to current methods.
The code will also be used to investigate design and control problems. For example, the coupling of large elastic deformations between different parts of an aircraft or stability control methods for flexible aircraft.
The motivation for this project is the need to increase aircraft efficiency. In order to do this, lighter airframes and higher aspect ratios must be used. In order for traditional flight dynamics laws to be used, the airframe must be stiff enough that the frequencies of the aeroelastics and the flight dynamics are dissimilar. By removing this stiffness constraint, more efficient aircraft may be designed at the cost of extensive consideration of the coupling between aeroelastics and flight dynamics. Analysing this is currently challenging, and is therefore a constraint the industry's ability to improve aircraft efficiency.
The purpose of the proposed project is to reduce the computational cost of the analysis of combined flight dynamics and aeroelastics for highly flexible aircraft through the use of alternative, lower order methods.
The project would initially involve investigation into the state of the art low order structural dynamics and fluid dynamics methods. Based on the outcome of the literature review, methods would be chosen to investigate, extend and implement within a computer code.
The code will then be verified, most probably using data collected from a highly flexible model aircraft built by a team at the Institute of Aeronautical Technology in Brazil. It is likely that the code may become complex due to the need to be able to model a full model in comparison to a "toy" case. Once verified, the code will be compared to current methods.
The code will also be used to investigate design and control problems. For example, the coupling of large elastic deformations between different parts of an aircraft or stability control methods for flexible aircraft.
The motivation for this project is the need to increase aircraft efficiency. In order to do this, lighter airframes and higher aspect ratios must be used. In order for traditional flight dynamics laws to be used, the airframe must be stiff enough that the frequencies of the aeroelastics and the flight dynamics are dissimilar. By removing this stiffness constraint, more efficient aircraft may be designed at the cost of extensive consideration of the coupling between aeroelastics and flight dynamics. Analysing this is currently challenging, and is therefore a constraint the industry's ability to improve aircraft efficiency.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509668/1 | 01/10/2016 | 30/09/2021 | |||
| 1944318 | Studentship | EP/N509668/1 | 01/10/2017 | 31/03/2021 | Hugh Bird |
| Description | Simplified aerodynamic models neglect certain aspects of physics. Using these models, solutions can be obtained far more quickly than would otherwise be possible. The problem however, is knowing how accurate this more easily obtained solution is. The accuracy of unsteady lifting-line theory, and how different wake simplifications affect the accuracy of these theories has been examined. Additionally, new theories have been constructed that overcome limitations of earlier theories. Most past unsteady lifting-line theories are in the frequency domain, but many practical problems are in the time domain. New theories that use the teachings of frequency domain theories have been constructed in the time domain. |
| Exploitation Route | For purely aerodynamics, some previous authors have taken an ad-hoc approach to constructing unsteady lifting-line theories. Portions of this works should help guide them in the construction of their methods and understand the limitations of other methods. Models created can also be applied to practical problems. These include the aerodynamics and structural dynamics of aircraft, wind and tidal turbines, flapping energy harvesting devices and flapping micro air vehicles. |
| Sectors | Aerospace, Defence and Marine,Energy,Security and Diplomacy,Transport |
| Title | CVortex |
| Description | An accelerated vortex particle code. CVortex takes advantage of multi-core CPUs and GPUs to compute the interaction between regularised vortex particles quickly. The regularised vortex particle method allows unsteady aerodynamic problems to be studied at a very low computational cost in comparison to conventional finite volume codes. Additionally, it is mesh free(requiring less pre-processing) and is easier to use. The library is cross platform (with pre-compiled binaries available for Windows and Linux on AMD64), is compatible with multiple GPU vendors (Intel, AMD, Nvidia tested) and is designed to be easy to use. This is in comparison to competing libraries which are typically Linux only and require computer hardware from specific vendors. The library is written in C. A wrapper for the Julia programming language was also written (https://github.com/hjabird/CVortex.jl), making its installation as easy as "add CVortex". |
| Type Of Technology | Software |
| Year Produced | 2019 |
| Open Source License? | Yes |
| Impact | The library is intended to be used primarily via the CVortex.jl wrapper that is available in the Julia language's default repository. Consequently, the extent to which the library is used cannot be tracked. Within my own work, the library has either increased productivity by being up to x1000 faster than the original implementation or has allowed larger problems (~x100) to be studied within the same timeframe without impacting the portability of the code using it. |
| URL | https://github.com/hjabird/cvortex |