Engineering methods for SACCON configuration - Some Design Considerations

2019

AEAT

Purpose The purpose of this paper is to characterise the effects of mission and performance parameters on the design space of low observable subsonic unmanned combat aerial vehicles (UCAVs) operating in typical Hi-Lo-Hi ground strike missions. Design/methodology/approach Conceptual design methodologies appropriate to low observable, tailless UCAVs have been integrated into a multidisciplinary aircraft design environment, GENUS, developed at Cranfield University’s aircraft design group. A basic Hi-Lo-Hi mission is designed and a baseline configuration is established through the GENUS framework. Subsequently, an evolutionary optimiser and a robust gradient-based optimiser are used to obtain convergent design solutions for various leading edge sweep angles, mission ranges, cruise Mach numbers and other operational constraints. Findings The results indicate that performance constraints, specifically in the form of specific excess power (SEP), have a large influence on the overall sizing of subsonic tailless UCAVs. This requirement drives the engine sizing, which represents a considerable proportion of the empty and gross mass of the vehicle. Cruise Mach number studies show that no significant advantages exist for operating at low speeds while maintaining performance requirements consistent with combat missions. There is a drastic increase in the vehicle’s mass and thrust requirements for flight speeds above Mach 0.8, with low sweep configurations showing a more pronounced effect. Increases in the range are not overly dependent on the leading edge sweep angle. Top-level radar cross section (RCS) results also favour configurations with higher leading edge sweep angles, especially from the nose-on aspect. Finally, research and development costs are shown to be directly linked to engine size. Originality/value This research shows the use of an integrated aircraft design environment that incorporates aerodynamics, performance, packaging and low observability aspects into the optimisation loop. Through this methodology, this study supports the efforts towards characterising and establishing alternate visions of the future of aerial warfare through the use of low cost, survivable unmanned platforms in network-centric cooperative tasks.

Section: Mass Estimationmentioning

confidence: 99%

Section: Aerodynamic Modellingmentioning

confidence: 99%

Impact of mission requirements on the design of low observable UCAV configurations

Palacios

2019

AEAT

“…Lower-fidelity methods have also been evaluated. These methods consist on potential flow solvers with compressibility and boundary-layer corrections (VSAERO, LIFTING_LINE), panel methods enhanced with leading-edge vortex separation and vortex breakdown models (Nangia-Aero-Panel, dwfs Panel), and vortex-lattice enhanced with empirical models (Tornado VLM, SHAMAN) (80,81) . Results show good agreement with lift and drag coefficients for low to moderate AoA; however, results for the pitching moment coefficient vary significantly due to non-linear flow phenomena that low-order methods cannot fully predict.…”

Section: Technology Challengesmentioning

confidence: 99%

Technology challenges of stealth unmanned combat aerial vehicles

Sepulveda

2017

Aeronaut. j.

The ever-changing battlefield environment, as well as the emergence of global command and control architectures currently used by armed forces around the globe, requires the use of robust and adaptive technologies integrated into a reliable platform. Unmanned Combat Aerial Vehicles (UCAVs) aim to integrate such advanced technologies while also increasing the tactical capabilities of combat aircraft. This paper provides a summary of the technical and operational design challenges specific to UCAVs, focusing on high-performance, and stealth designs. After a brief historical overview, the main technology demonstrator programmes currently under development are presented. The key technologies affecting UCAV design are identified and discussed. Finally, this paper briefly presents the main issues related to airworthiness, navigation, and ethical concerns behind UAV/UCAV operations.

“…Extensive use of this environment has been made and a broad list of publications are available demonstrating the capability of the environment. [28][29][30][31][32][33][34][35] Desktop Aeronautics developed the program for aircraft synthesis studies (PASS). 36 It is suited for conventional subsonic layouts, but is also capable of analyzing supersonic business jets or oblique wings.…”

Section: Introductionmentioning

confidence: 99%

The GENUS aircraft conceptual design environment

Proceedings of the Institution of Mechanical Engineers, Part G:

Sziroczák

Abbe

et al. 2018

The design of aircraft has evolved over time from the classical design approach to the more modern computer based design method utilising multivariate design optimisation. In recent years aircraft concepts and configurations have become more diverse and complex thus pushing many synthesis packages beyond their capability. Furthermore, many examples of aircraft design software focus on the analysis of one particular concept thus requiring separate packages for each concept. This can lead to complications in comparing concepts and configurations as differences in performance may originate from different prediction toolsets being used. This paper presents the GENUS Aircraft Design Framework developed by Cranfield University's Aircraft Design Group to address these issues. The paper reviews available aircraft design methodologies and describes the challenges faced in their development and application. Following this, the GENUS aircraft design environment is introduced, along with the theoretical background and practical reasoning behind the program architecture. Particular attention is given to the programming, choice of methodology and optimization techniques involved. Subsequently, some applications of the developed methodology, implemented in the framework are presented to illustrate the diversity of the approach. Three special classes of aircraft design concept are presented briefly.