HyperMach Aerospace is about halfway through a two-year program to validate crucial technologies for both its newly renamed HyperStar supersonic business jet (SSBJ) and the airplane’s hybrid turbofan ramjet engines being developed by sister company SonicBlue Aerospace. Richard Lugg, who heads both companies, told AIN that 2016 and 2017 are “pivotal years” for its SSBJ, which was previously known as the SonicStar.
Additionally, HyperMach has once again revised the aircraft’s preliminary performance and specifications upward, to a top speed of Mach 5 at 80,000 feet and 7,000-nm range. In late 2012, it boosted the SSBJ’s top speed estimate to Mach 4.5 and range to 6,500 nm from its original Mach 3.6 and 6,000 nm, when it announced the project at the 2011 Paris Airshow.
It also increased the size of the airplane in late 2012 to seat up to 36 passengers from the initial 20; it has not made any further changes to the basic configuration since then. The updated and now-current HyperStar design has a larger swooped delta wing, redesigned V tail and a pair of more powerful engines, compared with the original design. Both the larger fuselage, which will now carry center tanks, and wing allow for more onboard fuel that in turn helps to stretch the airplane’s range.
HyperMach plans to announce its airframe partner in the second quarter of next year. “The company has worked with the airframe manufacturer for all of 2016 in determining and laying out a successful development plan and examining in close detail the risks and benefit of detail design, schedule and airframe team, as well as the plan for the first flying prototype,” said Lugg.
HyperMach is now preparing to begin wind-tunnel testing of the HyperStar next year, with plans to begin hypersonic testing in May at a wind-tunnel facility in Europe. It is also slated to begin low-speed wind-tunnel tests in the U.S. in June and high-speed trials in Europe in April. The low- and high-speed analyses are slated to conclude later next year, while the hypersonic assessments are expected to take 30 months.
The high-speed wind-tunnel tests will also allow the company to further experiment with the electromagnetic drag reduction technology (EDRT) that it intends to use to mitigate, and possibly even eliminate, the sonic boom. With this core technology, a generated plasma ion field is pulsed around strategic fuselage, wing and tail surfaces to create active laminar flow control at the boundary layer interface. This changes the double pressure N-Shaped shockwave shape that emanates to the ground, dramatically reducing the over-pressure and mitigating the sonic boom. In addition, this plasma field will help reduce the heat on the HyperStar’s ceramic composite skin.
Lugg said that HyperMach engineers have demonstrated the EDRT flow control in a laboratory and found it be 90-percent effective at Mach 3.0 and above. The EDRT system, electrically powered by the additional overboard electricity from the H-Magjet engines, is a pulsed phased system, making it safe for aircraft occupants and certifiable under government regulation, according to the company.
To minimize cost and risk, HyperMach is taking an unusual step -- planning to fly an unmanned scale model of the HyperStar in late 2018. This flight vehicle will be flown in supersonic corridors so it can be tested at speeds up to Mach 5, the company said. Not surprisingly, the U.S. military has expressed interest in this unmanned scale vehicle, though Lugg insisted that this program is sufficiently walled off to prevent the military from prohibiting development of the civil HyperStar.
Meanwhile, Portland, Maine-based SonicBlue is busy developing and testing the critical technology built into the SSBJ’s 76,000-pound-thrust H-Magjet 5500-X hybrid turbofan ramjet engines. Lugg said the company holds “major patents” for its “revolutionary propulsion technology,” which includes a superconducting turbo power core ring to generate the aircraft’s high electrical power requirements.
“The first engine stage produces more than 10 megawatts of power, driving the electromagnetic compressor and bypass fans,” he noted. “There are five turbine stages in H-Magjet, all producing multi-megawatts of power.”
As with other companies working to certify a supersonic civil aircraft, engine emissions and Stage 4 noise requirements remain a concern. Lugg said that initial testing indicated that the H-Magjet engine is exceeding both limits, but the SonicBlue team is working to minimize emissions and noise as it finalizes the engine design.
It is developing an ion plasma injection combustor to provide the “highest efficiency and performance in combustion for significant thrust gains,” Lugg told AIN. “By electrically atomizing and controlling the ionization to the point of fuel combustion and a controlled flame front powered by an electric arc field with electricity directly from the engine, thrust improvement along with significant emissions reduction is gained.”
He added, “We have completed final detail design of the first stage turbine core for testing. Manufacturing of this first stage has begun and is expected to be finished next month, with testing on the rig as early as February. All five stages will be completed through 2018, with complete turbine core test in the fourth quarter of 2018.”
A full engine run is scheduled for 2019, and Lugg said that his company has spent the last year working with new industry partners and hiring team members for the superconducting turbine core.
First flight of the HyperStar is now expected in 2025, with certification and entry into service slated to follow in 2028, he said. Both estimates are three years later than what was announced previously. HyperMach has begun to take orders for its SSBJ, and Lugg said he soon expects to close the company’s “first multi-aircraft unit order with a leading global private charter firm.” Current price of the HyperStar is $180 million, though that will escalate to $220 million sometime before the Paris Airshow in June.