SR-72 Confirmed: Mach 6 Project Blackswift

a reply to: anzha

This is neat. I hope they actually test one and find out.

a reply to: RadioRobert

May have already done so.

It would explain something.

a reply to: anzha

www.thedrive.com...

Investigation of the mixing characteristics in a transverse hydrogen injection combustor with an inlet compression ramp

Authors:

Zhao et al

Abstract:

A shock-enhanced mixing in a transverse hydrogen injection combustor with an inlet compression ramp is carried out by using Large-eddy simulation (LES). Effects of a shock train induced by the inlet compression ramp on the mixing process have been investigated at three jet to cross-flow momentum flux ratios, J. The counter-rotating vortex pairs (CVP), promoting the mixing process of the fuel jet plume and mainstream air, is significantly affected by the reflected shock. The vorticity analysis is constructed to further understand the turbulent mixing mechanism. The shock-induced baroclinic torque is found to play an important role on the generation of the vorticity in the near field of the fuel jet, and the place where the reflected shock interacts with the jet plume. In addition, the probability density function (PDF) of mixture fraction is also investigated.

www.sciencedirect.com...

Hybrid passive-active control method of a swept shock wave-supersonic wake interaction

Authors:


Soutodeh et al

Abstract:

In the present study, a hybrid passive-active flow control method is used to investigate the interaction between a swept shock wave (SSW) generated by a swept compression wall, and a supersonic wake formed by a wake generator (WG), using a three-dimensional finite volume code. In order to detect the turbulence in the flow behavior, the Reynolds stress model (RSM) is used. Furthermore, dynamic mesh adaptation (DMA) and full multigrid (FMG) techniques are used to better predict the flow structure. The numerical simulations are validated with available data and acceptable agreements are found. After ensuring the accuracy of the numerical code, the effects of the variations in the wake generator's height and temperature, as a hybrid passive-active flow control method, on a swept shock wave and a supersonic wake are investigated. The results indicate that any change in the height and temperature of the wake generator affects the Mach number distribution, the static and the stagnation pressures, as well as the shock's position.

www.sciencedirect.com...

Note where the good researchers are located. And someone needs to have a chat with the RoK about one of them.

a reply to: anzha

Is the SABRE concept from Skylon relevant to a potential US hypersonic plane?

I know it is primarily a SSTO proposal, but I read somewhere that the US might be looking at it for hypersonic flight.

a reply to: beetee

At the moment AFRL/DARPA have thrown money at them, but it's just to demonstrate thr pre-cooler. I don't think the interest is there for SABRE as a whole. I don't think that is destined change, but who knows.

Either way, getting someone to pay for the sort of test rig needed to demonstrate the pre-cooler is no small accomplishment. And will help them immensely in getting other sources of funding to try to demonstrate SABRE in the future.

(PS-- Skylon is dead)

a reply to: RadioRobert

(PS-- Skylon is dead)

Yes, I know it is an "abandoned" concept. But if.the SABRE engine concept is as efficient as has been claimed, I bet it could rise from the dead even if we are never officially notified.

Everybody and their uncle is scrambling to get ahead in the coming space arms race, and a true SSTO reliable platform would just be too good an advantage to pass up, in my opinion.

ETA: There are no shortage of suggested applications, at least :-) Link

Double

They've done well nursing it along this far. Between ESA money and getting BAE, Boeing, and RR to buy-in. Took a long time and lots of money, but they might get something that flies.

As for applications, it'll depend on how it all shakes out.

Flameholding characteristics of ethylene-fueled model scramjet in shock tunnel

Authors:

Kim et al

Abstract:

The flameholding characteristics of a model scramjet were investigated experimentally. Experiments were performed in a shock tunnel at a nominal freestream Mach number of 4. The considered total enthalpy was approximately 1.7 MJ/kg. The test model consisted of a double ramp inlet, combustor with cavity, and cowl. The investigated fuel was ethylene, with a fuel–air equivalence ratio ranging from 0.05 to 0.21. Shadowgraph and flame luminescence images were obtained. The effects of injection location, angle, and equivalence ratio on flameholding were investigated. As the equivalence ratio was increased, the flame signals in the cavity shear layer strengthened with a near-constant spreading angle for inlet injection. The flame was maintained at the shear layer above the cavity. Unlike in the inlet case, the cavity upstream injection indicated that the flame was quite unstable during steady flow, and in general, the flame height downstream of the cavity increased as the equivalence ratio increased. In line with the literature, the flame stabilization mode for inlet injection was categorized as a “cavity shear layer-stabilized flame,” while the cavity upstream injection was a “combined cavity shear layer/recirculation zone-stabilized flame.” The effect of the injection angle on flameholding indicated that transverse injection exhibited superior fuel–air mixing compared to angled injection for the inlet case. With cavity upstream injection, the flame was effectively maintained for both the transverse and angled injections, with approximately equivalent flame spreading angles downstream of the cavity.

www.sciencedirect.com...

a reply to: RadioRobert
They were building new Test buildings in the Uk last I heard.
Test Facility 1
Test Facility 2 is in Colorado.

a reply to: Blackfinger

I wouldn't call RE dead.They did get a series B funding last year for the tune of $37M from Boeing, RR, etc.

They were claiming a ground test of the full engine in 2020. I'd be hesitant to believe that. However, they are tenacious.

Their Skylon concept has a lot of flaws (mass fraction, assuming potentially unobtainium for structural materials, etc), but calling the company toast is ... not what I'd say.

a reply to: anzha

REL has gotten money from several major players recently. They aren't dead.

Skylon is dead, though. They've stopped promoting it entirely. Erased all trace on their own domains, don't show it at trade shows, etc.

If they can get the precooler to function as designed, they'll get plenty of money even if SABRE entirely flops. Because not only can you adapt it for the needs for other aero-engines, that same base technology has other applications as a heat-exchanger. It can theoretically at least be smaller and lighter than other heat-exchangers and/or offer higher efficiencies. So everything that uses one (cars, trucks, electrical plants, industrial equipment, spacecraft/satellites, ...) represents a potential market for their technology.

But Skylon is never going to happen. It was just a marketing tease. I doubt it was ever a serious project, to be honest, but that's what got them press attention. "I have a unique engine scheme and really nifty pre-cooler" doesn't get Popular Mechanics to give you millions in free advertising. Mount that on a futuristic looking SSTO, and you get on PopMechanics, NYT, WSJ, etc What is basically a small start up chasing a big project needs that sort of attention to drum up investors and stay alive. What's the market on combined cycle scramjet/rockets look like? Pretty niche. Hard to pry money from investors. Get your name in the papers with Skylon, on the otherhand, and people who have more money than sense and big dreams start to think of it as a pet project.

They've slowly, but surely made it this far. Now that they've demonstrated some level of feasibility for the pre-cooler, they've dropped the charade and marketing to be considered more "respectable" by the professionals they need to bring this to fruition. That's working, too. DARPA/DOD funding, BAE, RR, Boeing investments, etc. The money is coming in, and they'll need every penny for now. All the investors stand to get very rich if they make this thing work. Engines and spaceplanes or no.

Im waiting to see if Magjets starts physical testing anything publicly.

twitter.com...

Lockheed-Martin booth at the Air Warfare Symposium...

HTV-2 apparently...

That or "Oh Jesus we need to have a high speed model in our booth"...

a reply to: Blackfinger

X-60A completes CDR:

afresearchlab.com...

www.parabolicarc.com...

a reply to: Blackfinger


Oh look, a big, black triangle from Lockheed!!

LOL!

Sonic glider my backside...

@anzha, keep on posting!

Drag and heat flux reduction induced by the pulsed counterflowing jet with different waveforms on a blunt body in supersonic flows

Authors:

Zhang et al

Abstract:

The drag and heat flux reduction characteristics plays a very important role in the conceptual design phase and engineering realization of the aerospace vehicle. In the current study, the flow field properties around a blunt body with three different pulsed counterflowing jets in the supersonic flow with the freestream Mach number being 3.98 are investigated numerically. In this paper, there are three different kinds of pulsed jets with the sinusoidal, triangular and rectangular waveforms are established, and the periods of the pulsed jets are all set to be T = 1.0 ms. The jet nozzle is placed at the nose of the blunt body. In the numerical investigation, an axisymmetric numerical simulation model of the counterflowing jet on the supersonic vehicle nose-tip is established, and the two-dimensional axisymmetric Reynolds-averaged Navier-Stokes (RANS) equations coupled with the two equation k-ω shear stress transport (SST) turbulence model are employed. The wall Stanton number distributions, as well as the surface static pressures, are extracted from the flow field structures in order to evaluate the drag and heat flux reduction characteristics. Further, the influence of the pulsed jet waveform on the drag and heat flux reduction is analyzed based on the wall Stanton number and surface pressure distributions. The obtained results show that the variations of the wall Stanton number and surface pressure distributions induced by the pulsed jet with the same period but different waveforms, all have an obvious periodicity and hysteresis phenomenon. At the same time, it is found that the drag and heat flux reduction under the triangular wave has the best effect, and the pulsed jet with the triangular wave has a better comprehensive performance than the other two waveforms.

www.sciencedirect.com...