13 juillet 2021 | International, Aérospatial, Naval, Terrestre, C4ISR, Sécurité
Contracts for July 9, 2021
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2 août 2019 | International, Aérospatial
European Hypersonic Cruise Passenger Study Set For New Tests
By Guy Norris
A team of European hypersonic researchers are preparing for wind tunnel tests of a Mach 8 concept that is designed to prove technologies for the development of future ultra-long-range, high-speed commercial vehicles and air-breathing space launch systems.
Funded under Europe's Horizon 2020 research and innovation program, Stratofly (Stratospheric Flying Opportunities for High-speed Propulsion Concepts) is targeted at fostering hypersonic capabilities for a 300-seat passenger vehicle cruising above 30 km (19 mi.) to TRL (technology readiness level) 6 by 2035. The project builds on the Lapcat waverider concept developed under earlier programs by the European Space Agency/European Space Research and Technology Center.
Using the 310-ft.-long Lapcat II MR2.4 version as a reference vehicle, the 30-month Stratofly effort is focused on classic hypersonic technology challenges such as propulsion integration, hot structures and thermal management. In addition, with environmental concerns at the forefront in Europe, the project also includes sustainability considerations such as fuel-burn efficiency, noise and emissions reductions, as well as operational issues such as life-cycle costs, safety and certification.
Coordinated by The Polytechnic University of Turin, Italy, the project team believes that sustainable hypersonic travel is feasible through the use of liquid hydrogen fuel and new trajectories that would enable flights from Europe to Australia in 3 hr. Specific targets include 75-100% CO2 reductions per passenger kilometer and 90% reductions in nitrous oxide (NOx) compared to current long-range transport aircraft. A version of the vehicle could also be adapted into the first stage of a two-stage-to-orbit space launch system, says the group.
Other members of the 10-strong consortium include the von Karman Institute for Fluid Dynamics in Belgium, which is focused on propulsion and noise; the Netherlands Aerospace Center, NLR, which is also part of the noise study; and CIRA, the Italian aerospace research center, which is conducting high-speed flow analysis. Propulsion systems and climate impact input is provided by Germany's DLR research organization, while ONERA, the French aerospace research center, is focused on emissions as well as plasma-assisted combustion in the vehicle's combined-cycle propulsion system. Sweden's FOI defense research agency is also part of the plasma combustion study.
The French National Center for Scientific Research is also evaluating the vehicle's potential climate impact, particularly in areas such as the effects of water droplets from the exhaust in the upper atmosphere. Studies of the overall business plan, human factors and hypersonic traffic management are being conducted by the Hamburg University of Technology, while the Spain-based Civil Engineering Foundation of Galicia is focused on structural analysis and optimization.
Like the original Lapcat design, the Stratofly MR3 waverider configuration is dominated by a large elliptical inlet and an integrated nozzle aft located between two canted tail fins. For takeoff and acceleration up to Mach 4.5, the vehicle is powered by six air turbo ramjets (ATR, also known as air turbo rockets) in two bays of three, each fed by secondary inlets in the primary intake. Above this speed, sliding ramps cover the ATR inlets as the vehicle accelerates and transitions to a dual-mode ramjet/scramjet (DMR) for the next phase of the flight.
The DMR is housed in the dorsal section, nested between the ATR ramjets, and is designed to operate in ramjet mode to above Mach 5 and scramjet mode up to Mach 8. The scramjet will incorporate a plasma-assisted combustion system to maintain the stability of the flame front and prevent the potential for flameouts. Tests of the plasma system in a combustor will take place later this year at ONERA, where supersonic combustion testing also took place for Lapcat. The tests will be conducted in November-December at ONERA's ATD5 facility and will focus on inlet conditions at Mach 3.7.
Also planned for later this year is a test of the full vehicle in the high-enthalpy wind tunnel at DLR's Gottingen research facility. Testing at DLR will run through September 2020 and is expected to target similar free-stream conditions as those tested on Lapcat II—around Mach 7.8. The work will assess aerothermodynamic characteristics and be used to validate the results of earlier computational fluid dynamics analysis of the MR3 design, which incorporates external and internal differences against the reference vehicle.
“We elevated the canard [a retractable feature for lower-speed flight] and redesigned the vertical tails,” says Davide Ferretto, a research assistant on the Stratofly team from The Polytechnic University of Turin. “We also redesigned the leading-edge radius of the inlet for increased efficiency as it feeds both propulsion systems.” As part of the redesign, the enclosed passenger compartment, which was divided into two sections running along each side of the vehicle, has been combined into a single cabin in the lower lobe of the fuselage.
https://aviationweek.com/propulsion/european-hypersonic-cruise-passenger-study-set-new-tests
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4 février 2021 | International, Aérospatial
Air Force study on future aerial refueling tanker could start in 2022
By: Valerie Insinna WASHINGTON — The Air Force could begin to lay out its vision for a future aerial refueling tanker, previously known as KC-Z, as early as next year, the head of Air Mobility Command said Monday. The service intends to conduct an analysis of alternatives for an advanced aerial refueling aircraft in fiscal year 2022, AMC commander Gen. Jacqueline Van Ovost said during a Defense Writers Group meeting with reporters. That study will help the Air Force determine precisely which capabilities a future tanker will need to to operate in more heavily contested battlefields against the threats posed by nations such as Russia and China. “We're thinking about the near peer [competition], and what we need for a near peer [competition],” she said. Key to that discussion is figuring out how much of the aerial refueling process can be performed without a human pilot or boom operator onboard the plane to fly it or give other aircraft gas. “Is going to be autonomous? Is it going to be pilot on the loop [or] pilot in the loop capability?” asked Van Ovost. “Is it going to be small? Is it going to be large? What kind of [self protection] is it going to have? What kind of electromagnetic spectrum capabilities is it going to have to both protect itself and enhance the lethality of the Joint Force while it's out there?” In April, Will Roper, then the Air Force's top acquisition official, told reporters that an agreement with Boeing for a new and improved KC-46 vision system could pave the way for autonomous aerial refueling. The addition of 4K high-definition cameras, modern processors and LiDAR (light detecting and ranging) sensors would help the new system accumulate much of the data necessary for a computer to correctly calculate all the variables that need to be solved for safe aerial refueling. “All you have to do is take that data that tells the world inside the jet the reality of geometries between the airplane and the boom outside the jet. Once you have that, you simply need to translate it into algorithms that allow the tanker to tank itself,” Roper said then. The Air Force is not the only service interested in automated aerial refueling. The Navy is flight testing the MQ-25 Stingray aerial refueling drone — which, like the Air Force's new KC-46 tanker, is built by Boeing. The Navy eventually hopes to operate the MQ-25 onboard aircraft carriers, where it will be used to extend the range of fighter jets like the F-35C and F/A-18EF Super Hornet. Van Ovost acknowledged the Air Force is still years away from being able to hold a competition for the platform formerly known as KC-Z. After the Air Force completes its procurement of 179 KC-46s — which, if its current buy rate holds, will occur around the 2027 timeframe — the service will buy a non-developmental “bridge tanker,” she said. That effort, which replaces the KC-Y program, will likely be a battle between Boeing and an Airbus-Lockheed Martin team, which joined forces in 2018 to market Airbus' A330 Multi-Role Tanker Transport to the U.S. Air Force. Both teams are expected to offer upgraded versions of their current aerial refueling aircraft. Van Ovost did not say when that competition will begin. Along with tackling questions about its future tanker, the Air Force is also set to begin a business case analysis whether to pursue contracted aerial refueling to support U.S. military training and test activities across the contiguous United States. After holding a Dec. 19 industry day with interested vendors, Air Mobility Command conducted a study into the feasibility and affordability of commercial air refueling services and submitted a proposal to Air Force leadership. However, Air Force leaders want more information before making a final decision, and have asked for a comprehensive business case analysis that would finalize a requirement for all of the services' needs, Van Ovost said. The study would come up with options for various contracting models — which could include tankers that are leased to the government or contractor-owned and operated — as well as hammer out details on Federal Aviation Administration certification requirements. “We're working with headquarters Air Force to finalize the parameters for the study, and then likely will be contracting out that study,” Van Ovost said. “And for expectation's sake, it does take a while. These kinds of business case analysis we have seen take 18 months, so we are going to put pen to paper and take a very close look at it.” https://www.defensenews.com/air/2021/02/02/air-force-study-on-future-aerial-refueling-tanker-could-start-in-2022/
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22 août 2023 | International, Aérospatial
Opening up National Security Space Launch program endangers access
A former U.S. Air Force secretary argues against allowing a vendor who has not yet successfully launched to compete on the basis of a paper proposal alone.