Conference Publications

Permanent URI for this collection

http://hdl.handle.net/10204/11486

Browse

Browsing Conference Publications by browse.metadata.impactarea "Aerospace Systems"

Now showing 1 - 8 of 8
  • No Thumbnail Available
    Item
    Evaluation of guidance, navigation, and control algorithms for hydrogen-powered multi-aircraft systems
    (2025-09) Makhubo, Mamokete; Ndebele, Bright B; Ragimana, Phumudzo
    This paper presents a modular digital-twin framework to compare inner-loop attitude controllers: geometric PD (“PID”), discrete Linear-Quadratic Regulator (LQR), and a movepenalized linear Model Predictive Controller (MPC), for a heavy-lift T30-class quadcopter intended for hydrogen propulsion study. The twin couples 6-DoF rigid-body dynamics, actuator mixing, motor/ESC lag, a bus-level electrical model, and stochastic wind (OrnsteinUhlenbeck) with look-ahead guidance on a sharp lawnmower survey. To isolate controller effects, task difficulty is equalized by autotuning a single scalar so that the achieved cross-track Root-Mean-Squared Error (RMSE) lies in a 2.6 ± 0.25 m band. The tuned controllers then run identical 600 s simulations under the same wind seed and retimed speeds. On the equalized run, PID and LQR achieve 2.45 m and 2.55 m RMSE, respectively, while MPC settles at 3.13 m due to its move penalty and finite horizon. All three deliver survey-class performance with mean bus power ≈ 4.8 kW and peaks in the 7–8 kW range, but MPC reduces energy per meter by approximately 2.3% at the cost of relaxed lateral accuracy. A 10-seed Monte Carlo confirms this trade: PID/LQR remain in-band for 90%/80% of seeds, while MPC consistently lowers energy per meter with similar mean power but gentler peaks. For hydrogen-electric UAVs, these metrics map directly to propulsion co-design, where energy per meter informs hydrogen mass and range, peak power sets stack/buffer sizing, and actuator smoothness affects balanceof-plant transients. The results show that controller selection is not only a matter of tracking accuracy but also an energy-management lever: PID/LQR suit survey tolerance, while MPCstyle penalization favours endurance and balance-of-plant stability.
  • No Thumbnail Available
    Item
    Flutter clearance techniques and tools for gliders
    (2024-08) Van Zyl, Louwrens H
    The flutter clearance of gliders pose some special challenges. Modal frequencies are low, making suspension of the glider for ground vibration testing challenging. The low frequencies also make large amplitudes of excitation desirable. In flutter flight testing space for excitation systems and telemetry systems is limited.
  • No Thumbnail Available
    Item
    Internal aircraft cavity bay tests in the medium speed wind tunnel (MSWT)
    (2024-08) Mashilangwako, Kgoane J
    Continuous improvements in the wind tunnel facility capability gives a corresponding improvement and expansion on the types of tests that can be performed, and the accuracy, precision and quality of the data one can get from a wind tunnel test.
  • No Thumbnail Available
    Item
    On the existence of a family of ideal aircraft configurations
    (2024-09) Huyssen, Reinhard J; Spedding, GR
    The bulk of fossil fuel in aviation is consumed in the domain of fixed-wing subsonic flight. Environmental concerns put strong incentives on the industry to improve flight efficiency. Best flight efficiency can only be attained if an aircraft design is based on its ideal configuration. Already since the middle of the previous century, the industry became entrenched in the tube-and-wings configuration, here referred to as the Current Dominant Configuration (CDC). It is widely speculated that better arrangements of wings and bodies exist, and many research initiatives are dedicated to the exploration of alternatives. These are typically done for specific types of aircraft, mostly for the airline industry. Yet, new aircraft developments keep employing the CDC as if proposed alternatives are ignored. Here a hypothesis is tested which suggests that a single family of aircraft configurations exists which is ideal for the majority of economically significant flight objectives within this domain. To organise the aircraft design space into families of configurations, a hypothetical Ideal Wing is introduced as a common basis from which all configurations evolve by inflation to provide practical flyers with volume for their payload. While the most prominent configurations, including the CDC, appear to disqualify as candidates for the proposed ideal configuration, the one which qualifies, has not been seriously examined in human aviation, although it is familiar. Termed the Natural Dominant Configuration, as it appears in natural flyers, it certainly merits further exploration.
  • No Thumbnail Available
    Item
    The benefits of replacing the traditional dimensional calibration system with the Laser Measurement Technology in the CSIR Wind Tunnel Facilities
    (2024-09) Ragimana, Phumudzo; Mabeko, Philimon K; Dikgale, Moyahabo S
    Calibrations in any aerodynamic metrology field require patience as it is time-consuming. The Council for Scientific and Industrial Research has wind tunnel facilities with a wind tunnel model support system of 6 degrees of freedom. These degrees of freedom are three translations and rotations, which must be calibrated per project-specific requirements and the facilities maintenance management schedule. This paper addresses the impact of introducing advanced laser measurement technology instead of traditional dimensional instrumentation calibration systems at the CSIR Wind Tunnel Facilities. Conventional calibration methods typically entail extensive manual processes and significant downtime, resulting in higher operational costs and slower instrumentation calibration and wind tunnel testing cycles. The advantage of implementing the laser tracker system is that it enhances the calibration accuracy in the CSIR Wind Tunnel facilities. Therefore, the laser tracker system addresses these challenges and offers an efficient alternative. By enhancing precision and speed, the new technology improves the wind tunnel facilities’ dimensional instrumentation maintenance processes and aerodynamic testing while delivering substantial cost and time savings. Manual and time-intensive traditional methods incur higher costs, slower calibration processes, and limited precision and human errors. Laser measurement technology simplifies these tasks, producing faster and more precise calibrations. Through several calibration activities and data collection, it is evident that this replacement enhances instrumentation calibration efficiency and decreases operational expenses, representing a valuable improvement for future aerospace research and development.
  • No Thumbnail Available
    Item
    The benefits of replacing the traditional dimensional calibration system with the Laser Measurement Technology in the CSIR Wind Tunnel Facilities
    (2024-09) Ragimana, Phumudzo; Mabeko, Philimon K; Dikgale, Moyahabo S
    Calibrations in any aerodynamic metrology field require patience as it is time-consuming. The Council for Scientific and Industrial Research has wind tunnel facilities with a wind tunnel model support system of 6 degrees of freedom. These degrees of freedom are three translations and rotations, which must be calibrated per project-specific requirements and the facilities maintenance management schedule. This paper addresses the impact of introducing advanced laser measurement technology instead of traditional dimensional instrumentation calibration systems at the CSIR Wind Tunnel Facilities. Conventional calibration methods typically entail extensive manual processes and significant downtime, resulting in higher operational costs and slower instrumentation calibration and wind tunnel testing cycles. The advantage of implementing the laser tracker system is that it enhances the calibration accuracy in the CSIR Wind Tunnel facilities. Therefore, the laser tracker system addresses these challenges and offers an efficient alternative. By enhancing precision and speed, the new technology improves the wind tunnel facilities’ dimensional instrumentation maintenance processes and aerodynamic testing while delivering substantial cost and time savings. Manual and time-intensive traditional methods incur higher costs, slower calibration processes, and limited precision and human errors. Laser measurement technology simplifies these tasks, producing faster and more precise calibrations. Through several calibration activities and data collection, it is evident that this replacement enhances instrumentation calibration efficiency and decreases operational expenses, representing a valuable improvement for future aerospace research and development.
  • No Thumbnail Available
    Item
    The effect of combustor hole-set arrangement when comparing two different hole-set design methods
    (2024-07) Meyers, Bronwyn C; Grobler, Jan-Hendrik
    This presentation focuses on the effect of combustor hole-set arrangement when comparing two different hole-set design methods.
  • No Thumbnail Available
    Item
    Urban Air Mobility: Regulatory Pathways and Readiness for Integration in South Africa
    (2025-07) Ndlovu, Hlamulo P; Niken, Adrian; Madonsela, N; Teane, Tshegofatso O; Moodley, Theolan
    Urban Air Mobility (UAM) refers to the use of small, electric or hybrid-electric aircraft, often highly automated, designed to transport passengers or goods at low altitudes within urban and suburban environments, which has been developed in response to traffic congestion in the cities. This presentation highlights work that forms part of the International Forum for Aviation Research (IFAR) project titled “Navigating the Skies: A Guide to Certification for Urban Air Mobility”.