Mark Jabbal

Active flow control of high-lift multielement swept wings remains a critical yet underexplored field in aerodynamics. This study investigates the effects of the duty cycle (DC) and the jet-to-freestream velocity ratio (VR) on pulsed jet flow control (PJFC) actuators near the leading edge of a multielement swept wing with three major innovations. First, a threshold effect is identified at [ ]. Below this threshold, a low DC actuation achieves comparable or superior maximum lift enhancement relative to a high DC operation. Second, mechanistic analysis reveals that at a high DC, the initial jet-induced vortex fails to merge with the dominant shear-layer vortex, leading to the emergence of an additional high-frequency shedding mode. In contrast, a low DC actuation increases the maximum lift coefficient by expanding the favorable suction pressure region, particularly at a lower VR. Third, PJFC delays the stall angle by approximately 4–6 degrees and achieves significant drag reduction at moderate angles of attack. These findings provide novel insights into the underlying mechanisms and enable a physics-informed selection of the VR and DC in effective active flow control on swept high-lift wings.

Recent analyses of the UK National Space Strategy [1], Space Sector Skills Survey [2] and The 2020 Space Census [3], have investigated and highlighted many of the established strengths and weaknesses of the current UK Space Sector and the role of training and educational programs supporting it. Furthermore, there is additional research into what self-reported roadblocks early career students and workers (and employers) consider important in this journey [4]. Academia, employers, schools, colleges, and museums all have considerable roles to play in shaping the future science capital of our populace and establishing people on the tech workforce pipeline. Rising to meet this challenge, The University of Nottingham wants to develop the UK's space workforce and is proud to have begun its first dedicated aerospace undergraduate course in 2016. In addition to the core lecture modules, added project experience is available in the form of group and individual supervised projects. These practical activities are a rare opportunity to learn unique space skills and work hands-on with spacecraft technology, something in short supply in the UK at the undergraduate level [2]. The practical, hands-on components are an important part of the space education programme and involve different platforms and projects going from simple electronics workshops to CanSats, FlatSats and experimental Rockets. These activities culminate in the CubeSat Program: a student-led group of projects to develop, build and fly CubeSat missions with a variety of payloads. The students have the possibility to present their own mission idea or join existing ones of interest to the research community. To support these high-fidelity opportunities for students and early career workers, a permanent on-site COTS Ground Station will serve as a control center for all these student-built satellite missions. To help with the establishment of this facility, The University of Nottingham has been cooperating with the local amateur radio community to train and license the student team. This paper deals with the description of the different projects and presents the University’s point of view about the strengths and weaknesses of our Space educational programme

This paper investigates the navigation performance of a vehicle dynamic model-based (VDM-based) tightly coupled architecture for a fixed-wing Unmanned Aerial Vehicle (UAV) during a global navigation satellite system (GNSS) outage for real-time applications. Unlike an Inertial Navigation System (INS) which uses inertial sensor measurements to propagate the navigation solution, the VDM uses control inputs from either the autopilot system or direct pilot commands to propagate the navigation states. The proposed architecture is tested using both raw GNSS observables (Pseudorange and Doppler frequency) and Micro-Electro-Mechanical Systems-grade (MEMS) Inertial Measurement Unit (IMU) measurements fused using an extended Kalman filter (EKF) to aid the navigation solution. Other than the navigation states, the state vector also includes IMU errors, wind velocity, VDM parameters, and receiver clock bias and drift. Simulation results revealed significant performance improvements with a decreasing number of satellites in view during 140 seconds of a GNSS outage. With two satellites visible during the GNSS outage, the position error improved by one order of magnitude as opposed to a tightly coupled INS/GNSS scheme. Real flight tests on a small fixed-wing UAV show the benefits of the approach with position error being an order of magnitude better as opposed to a tightly coupled INS/GNSS scheme with two satellites in view during 100 seconds of a GNSS outage.

The design, build and test of a smoke visualisation system for a vertical wind tunnel at Brunel University are described. The smoke visualisation system utilised a fog machine for smoke generation and required the design and manufacture of a smoke rake to produce smoke lines inside the wind tunnel test section. The application of these smoke lines over several test objects, including wing sections and bluff body shapes, demonstrated the functionality of the smoke system in producing high-quality visualisations. The facility has proven to be an economic addition in supporting other research projects and is anticipated to be a valuable ‘hands on’ addition to existing aerospace laboratory teaching.

This article documents the development of synthetic jet actuator array hardware to augment high-lift system effectiveness in a wind tunnel model. The study involved the design, manufacture and bench test of a synthetic jet actuator array based on an inclined actuator configuration to reduce volume installation requirements without a loss in jet velocity relative to a non-inclined baseline model; incorporation of proper synthetic jet actuator systems wiring and internal synthetic jet actuator chamber pressure-sensing for actuator health monitoring. The peak velocity obtained from the inclined synthetic jet actuator array was 100 m/s, which favourably compares to the baseline array (∼90 m/s), while reducing the usable depth requirements by 50%. The final outcome of this study has been to apply the design lessons learned to develop a methodology for designing a synthetic jet actuator array with the constraints of using piezoelectric-based actuator technology for flow separation control applications.