The layout design of a satellite module is a complex mechanical layout problem. Its main difficulties lie in combinatorial explosion of computational complexity, engineering complexity, and applicability in engineering practice. Inspired by the human-computer cooperation ideas, a human–computer co-operative co-evolutionary method for optimising layout design of a satellite module is developed. This method constructs the diversity reference set by using the diversity intelligence solutions (DIs) that are created by using the combinatorial operators of differential evolution (DE) and the blend crossover operator (BLX-a). During the co-evolution process of the presented method, the AIs, the DIs and the algorithm solutions are expressed by unified encoding strings and incorporated together to create new co-operative solutions. An instance of a satellite module layout design is presented to demonstrate the feasibility and effectiveness of the proposed method. Compared with the co-evolutionary approach and the all-at-once optimisation approaches, computational results show that the proposed method not only can produce better solutions, but also can better balance the conflicting objectives on the trade-off issues.

A forward facing spike attached to a hemispherical body significantly changes its flow field and influences aerodynamic drag and wall heat flux in a high speed flow. The dynamic pressure in the recirculation area is highly reduced and this leads to the decrease in the aerodynamic drag and heat load on the surface. Consequently, the geometry, that is, the length and shape of the spike, has to be simulated in order to obtain a large conical recirculation region in front of the blunt body to get beneficial drag reduction. It is, therefore, a potential candidate for aerodynamic drag reduction for a future high speed vehicle. Axisymmetric compressible laminar Navier-Stokes equations are solved using a finite volume discretisation in conjunction with a multistage Runge-Kutta time stepping scheme. The effect of the spike length and shape, and the spike nose configuration on the reduction of drag is numerically evaluated at Mach 6 at a zero angle-of-attack. The computed density contours agree well with the schlieren images. Additional modification to the tip of the spike to get different types of flow field such as the formation of a shock wave, separation area and reattachment point are examined. The spike geometries include the conical spike, the flat-disk spike and the hemispherical disk spike of different length to diameter ratios attached to the blunt body.

Corrugated structures offer a potential solution for morphing wing skin applications due to their anisotropic behaviour that allows chordwise camber and length changes. Aerofoils with corrugated skins in the aft 1/3 of the chordwise section have been studied experimentally and computationally using various corrugation shapes and forms (sinusoidal, trapezoidal and triangular) at different Reynolds numbers. The study showed that the aerodynamic performance is highly dependent on corrugation amplitude, wavelength, gradient (combination of amplitude and wavelength) and Reynolds number. Evidence is given highlighting that penalties for having a non-smooth surface in the aft 1/3 of the chordwise section of an aerofoil can be eliminated for the lift curve slope and minimised for the zero lift drag coefficient.

This paper presents the concept of using cylindrical pins as short protuberances for trajectory control of a blunted cone in the supersonic and hypersonic regimes. Supersonic and hypersonic flow interactions for cylindrical protuberances, installed on a blunt cone are studied for their aerodynamic effects. The utility of these protuberances for aerodynamic control and trajectory shaping of a re-entry cone are explored. Static aerodynamic coefficients in the Mach range of 2–9·7 at various incidences are computed. The pressure distribution along the vehicle longitudinal axis in the presence of the pin-protuberance is studied using CFD analysis. With the altered pressure distribution, a net increase in the aerodynamic force is obtained which can be actively utilised for flight control and maneuvering of the vehicle during re-entry. After quantifying the aerodynamic effects of the protuberance, it is modelled and used as an effective actuation mechanism for flight feedback control. It is shown that this can work as an effective control device for Mach numbers less than five. An actuator design for insertion/retraction of the protuberance is presented and modelled, and a robust controller is synthesised which can in real time govern the position of the protuberance to control the flight attitude angle to achieve a desired trajectory. The controller takes in measurements of the vehicle’s pitch angle and actuates the pin height continuously to control the pitch angle to a desired value. The control performance is demonstrated on a high fidelity six degrees-of-freedom (6-DOF) nonlinear flight simulation.

Mitigation of climate change is a challenge to science and society. Here, we establish a methodology, applicable in multi-disciplinary optimisation (MDO) during aircraft pre-design, allowing a minimisation of the aircraft’s potential climate impact. In this first step we consider supersonic aircraft flying at a cruise altitude between 45kfeet (~13·5km, 150hPa) and 67kfeet (~20·5km, 50hPa). The methodology is based on climate functions, which give a relationship between 4 parameters representing an aircraft/engine configuration and an expected impact on global mean near surface temperature as an indicator for the impact on climate via changes in the greenhouse gases carbon dioxide, water vapour, ozone and methane. These input parameters are cruise altitude pressure, fuel consumption, fuel flow and Mach number. The climate functions for water vapour and carbon dioxide are independent from the chosen engine, whereas the climate functions for ozone and methane depend on engine parameters describing the nitrogen oxide emissions. Ten engine configurations are taken into account, which were considered in the framework of the EU-project HISAC. An analysis of the reliability of the climate functions with respect to the simplified climate-chemistry model AirClim and a detailed analysis of the climate functions is given.

How long would it take to evacuate a blended wing body (BWB) aircraft with around 1,000 passengers and crew? How long would it take an external post-crash fire to develop non-survivable conditions within the cabin of a BWB aircraft? Is it possible for all the passengers to safely evacuate from a BWB cabin subjected to a post-crash fire? These questions are explored in this paper through computer simulation. As part of project NACRE, the airEXODUS evacuation model was used to explore evacuation issues associated with BWB aircraft and to investigate fire issues, the CFD fire simulation software SMARTFIRE was used. The fire and evacuation simulations were then coupled to investigate how the evacuation would proceed under the conditions produced by a post-crash fire. In conjunction with this work, a large-scale evacuation experiment was conducted in February 2008 to verify evacuation model predictions. This paper presents some of the results produced from this analysis.