Unmanned Systems Technology 019 | Navya Autonom Cab | Batteries | UGVs Insight | UAV Factory UAV28-EFI | Swiss Aerobotics Hummel | UMEX 2018 report | Antennas | Oceanology International 2018 report

20 In conversation | Saif-Deen Akanni spools to drive multi-stage centrifugal compressors. At small scales, centrifugal compressors are much more efficient than their axial equivalents because they are lighter, less susceptible to the effects of low Reynolds numbers and air leakage through the clearances between the blades and the casing. Akanni also cites the difficulty of achieving high compression ratios and air-fuel burn temperatures in such small engines. These are vital for absolute engine efficiency, but can reduce maintenance intervals. Key targets such as specific fuel consumption, thrust and power-to-weight ratio for example will depend on individual applications, but the company has been testing engines that can generate 6.5 kW and 9.5 kW of power continuously, the architecture of which can be scaled up or down depending on requirement. Knowing the rules Akanni’s Formula One background has provided ample experience of interpreting regulations to maximum advantage, and he sees plenty of scope for developing a long-range, high-performance UAV, even under the European Aviation Safety Agency (EASA) NPA 2017-05 and US Federal Aviation Administration’s Part 107 regulations that govern civilian use of unmanned aircraft. Although the rules are quite restrictive, limiting UAVs to 25 kg and prohibiting beyond-line-of-sight operations and flights above 500 ft or at night, Akanni notes that they are being applied with sensible caveats that allow for carefully thought-out exceptions. “For each of those restrictions there are special dispensations for companies or individuals engaged in commercial UAV activity to apply for waivers, and some aviation authorities are granting those waivers on a case-by-case basis,” he says. Sentient Blue’s current top priority is working with a UAV partner to get one engine design in the air within the next six months, and the company will be working with Italy’s ENAC and Europe’s EASA authorities on certification. After that, the company’s plan is to use that experience and supply chain to begin testing its own Quexada with the aim of displaying it soon, plans that Akanni says will have become firmer by the time you’re reading this article. April/May 2018 | Unmanned Systems Technology Saif-Deen Akanni is CTO of Sentient Blue. He has a BSc in mechanical and aerospace engineering from Cornell University, and a PhD in fluid dynamics from City University in London. From November 1992 he spent a year as head of aerodynamics at March Cars in the UK, managing the company’s Formula Three and Formula Atlantic experimental and computational fluid dynamics (CFD) programmes. His next full-time job in motorsport was as head of CFD for Sauber Petronas in Switzerland, between 1999 and 2002. He has also carried out consultancy and contracting work for CFD specialist Exa Corporation, Catia work on sports, touring and Le Mans cars for Audi Sport, and flight physics work for Airbus on the wings for the A320neo, A350 and A400M, and NH90 helicopter modifications for EADS/Eurocopter. Then came engine aero-elastic, aerodynamic and heat transfer studies on the F-35B fighter’s engine, and then testing and certification of the Trent XWB airliner engine at Rolls-Royce. Finite element analysis of armoured vehicles at General Dynamics followed, after which he worked on problems including heat transfer in submarine nuclear reactors, and aerodynamics and acoustics modelling for stealthy UAVs at BAE Systems, then on issues including forced response analysis of the high-pressure compressor of the Rolls-Royce BR700 NextGen engine. Most recently he was the senior aerodynamicist for the Haas-Ferrari Formula One team, a role he left in 2017 Saif-Deen Akanni Areas of equal temperature in a simulated combustor section, created as a visual aid to optimal placing of components such as vaporiser tubes and mixing jets for efficient combustion (Courtesy of Sentient Blue)