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Developing next generation , research 

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and technology , facilitating 

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connections between a FRL industry and 

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academia . Unlocking innovation through 

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a culture of collaboration . This is 

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the A FRL Regional Network Midwest . 

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My background is in energetic materials 

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in solid propellant , solid fuels . And 

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in this project , we're trying to 

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integrate uh solid fuels into uh 

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rotating detonation engines in solid 

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fuels . Why we're interested in that is 

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because they're much easier to store , 

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they don't leak . So if there's a 

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puncture in the device , you're not 

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going to have a fire hazard with that 

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potentially , it could have higher 

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energy density . But the challenge of 

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bringing in a solid fuel into the RD is 

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how do we integrate it in ? How do we 

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go from a solid fuel to a gaseous fuel 

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that the RD can operate with ? So 

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that's a big focus of this project is 

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looking at fuels that can gasify on 

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their own . So we don't have to bring 

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in energy to turn that fuel into gas , 

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but they burn , they propagate and 

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produce gas that can be fed into the 

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rotating detonation engine . Some of 

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the advantages of a rotating detonation 

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engine include increased thermal 

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efficiency due to the higher 

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temperatures and pressures that occur 

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during a detonation . In the video 

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shown here , for example , the 

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detonation wave is propagating at a 

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speed of over 1500 m per second , which 

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is over 3000 MPH . This is up to 100 

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times faster than the flame in a 

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typical engine which leads to increased 

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power density so that the combustion 

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can be made much more compact , simple 

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and lightweight than a normal combust , 

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which reduces the overall fuel 

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consumption . So the goal of the 

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research at Purdue University is to 

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investigate the types of solid 

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propellants that can be used in a 

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rotating detonation engine as well as 

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the systems that would be required to 

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incorporate those solid propellants 

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effectively in an operating rotating 

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detonation engine . For this project , 

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we're looking for solid fuel with some 

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pretty unique characteristics . First , 

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we wanted it to be able to self 

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defecate in a non oxygen atmosphere and 

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that's pretty important for how we will 

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get it to actually work in an RD . Um 

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We also wanted to produce very fuel 

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rich exhaust products , uh ones that 

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are hopefully very de like hydrogen gas . 

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Um And ideally , this is something that 

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we want to be able to produce in house . 

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Um That way we can kind of fine tune 

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the formulation or add in any type of 

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uh energetic additives as well . One of 

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the first things that we did for this 

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project was um essentially using a 

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synthetic mixture to simulate what we 

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think our solid fuel will produce in 

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the RD . So to do that , we use NASA CE 

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A which is a chemical equilibrium of 

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applications code in order to simulate 

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the propellant burning . And then we 

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were able to take that and take the , 

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the constituent gasses , mix them 

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together and fire that in an RD . So 

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that's one of something that one of my 

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previous colleagues did here at Purdue . 

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We have many RD that we're able to test 

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with . Specifically , we have optically 

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accessible ones , which is useful for 

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us to visualize what's happening inside 

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the RDE . And we use these in the solid 

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fuel project to do our tests . So one 

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of the next things that we did was use 

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Raman spectroscopy to actually measure 

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the products of our solid fuel NASA . 

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Because any software , especially one 

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that's kind of first order like NASA CE 

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A is going to produce results that are 

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not necessarily in line with reality . 

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So using Ramus photocopy , we're able 

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to very accurately measure the 

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concentration of all the different 

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species inside our solid fuel exhaust 

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products . And that kind of helps us 

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determine if we need to tweak the 

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formulation as well as will give us a 

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better understanding of I actually 

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operate inside an RD . One of the 

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things that we want to do is 

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characterize how detain those products 

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are . And so we use a detonation tube 

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which is essentially a long acrylic 

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tube that we're able to image with high 

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speed cameras to actually measure how 

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fast those exhaust products are able to 

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detonate . And in doing that , we're 

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able to kind of give ourselves a 

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benchmark for how well our formulation 

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is doing . And that kind of is an 

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important metric to understand how 

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we'll actually operate inside of A RD 

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once we get to that point . So our next 

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steps in the near term future is 

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scaling up our production of the solid 

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fuel that's going to allow us to do 

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larger scale tests as well as actually 

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integrate the solid fuel into the RD . 

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Um We're also been looking at various 

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additives that we can add to that solid 

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fuel formulation to produce exhaust 

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products that are more tailored to the 

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specific use case . Some of the 

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experimental setups that we've been 

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updating , we have a new raw and 

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spectroscopy setup that's going to 

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allow us to measure the solid fuel 

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exhaust products in a more realistic 

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environment . And that's going to give 

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us a better idea of the actual 

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formulation that we're working with 

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inside the RD . And then we also have a 

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larger det tube . Um that's gonna kind 

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of fix some of the issues that we first 

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saw in the original setup and allow us 

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to give , allow us to get more accurate 

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measurements of the wave speed of our 

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detonation . The idea to use uh solid 

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propellants for rotating detonation is 

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a fairly new one . So some of the 

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innovative work that's been done uh at 

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Purdue and a couple other places in the 

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US is really cutting edge technology . 

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So , um we've demonstrated burning uh 

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propellants um and producing something 

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that could then burn again in a , in a 

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rotating detonation engine . So that 

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proof of concept is really key to being 

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able to turn on , you know , additional 

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funds to , to , you know , do a more 

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substantive effort in maturing this 

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technology for , for an actual 

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application . Um There's a lot of work 

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been done with liquids , but rotating 

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detonation with solid fuel is is pretty 

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new , new game . It's a very high 

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interest technology across department 

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of defense . So uh it's a very 

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important technology for the war 

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fighter .