Why aren't pulsejet cruise missiles a thing?

For all our V1 lovers.
I was looking for the PBS TJ-200 and found out that the TJ-100 has an quite low SPFC tought that isn't my point. What i found interresting was the cost of the SubSonex JSX-2T as very small jet cost which is actualy around 137k $. Given that an unmanned version could safe some cost and space it could be very easy to upgrade into a cruise missile with an +700km range and atleast 250-500Ib warhead. For even lower cost the engine would have to change (no surprise there) but do we get the same capabilitys Out of it without too large problems. Because if one could change it too an pulse jet with just ⅓ the cost could reduce the total price by 50k $ (as the TJ-100 has a 75k price tag based on SubSonex website).

But that would need a 260Ibf pulse jet (atleast)
 
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OliverSedlacek said:
I'd be looking at this for really low cost ! ST ISM330BX 6-axis IMU
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Oliver, DARPA is looking into pulsjet engines for low cost propulsion units for certain UAVs.
Unfortunately, they seen most interested in the Lockwood-Hiller unit. I'm attempting to get into contact with them so that I might demonstrate my unit for them...(much better) overall.
Kevin Hambsch
 
KHambsch said:
Oliver, DARPA is looking into pulsjet engines for low cost propulsion units for certain UAVs.
Unfortunately, they seen most interested in the Lockwood-Hiller unit. I'm attempting to get into contact with them so that I might demonstrate my unit for them...(much better) overall.
Kevin Hambsch
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Kevin, I don't think DARPA is going to be the sort of organisation that does 'low cost' anything. As a civilian I know nothing about how big a warhead is useful or how much it costs. 'Useful' range depends on geography, and at the top of my mind is the Ukraine invasion. If I get the time I may try and figure out some numbers to see what the pulse jet Vs turbojet costs look like.
I'm thinking 'Scrapheap challenge', not BAE Systems.
 
OliverSedlacek said:
Kevin, I don't think DARPA is going to be the sort of organisation that does 'low cost' anything. As a civilian I know nothing about how big a warhead is useful or how much it costs. 'Useful' range depends on geography, and at the top of my mind is the Ukraine invasion. If I get the time I may try and figure out some numbers to see what the pulse jet Vs turbojet costs look like.
I'm thinking 'Scrapheap challenge', not BAE Systems.
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Yes and no. What DARPA wants is the capabilities. Usually that means expensive stuff to get what they want to do.

But if you demonstrate more range from a cheaper engine, they will be all over that because it has more range.
If you demonstrate equal range from a cheaper engine they might want it, depends on how many more units they can buy with the cheaper engine.
If you can't equal the range of the unit they're using, DARPA will hard pass, even if your engine is 1/10 the cost.
 
Elysium said:
Why aren't pulsejet cruise missiles a thing? Rockets are limited in range, as are glide bombs, both of which seem to be popular choices for low to mid-end weapons. On the other hand, turbofan-powered cruise missiles offer great range, but the engines themselves add a tremendous amount of cost to the weapon. Pulsejets are easy and cheap to manufacture, and I think they could carve out a healthy niche of inexpensive cruise missiles with decent range. So why aren't they used? Or maybe they are? Is there or has there been an attempt to build such a weapon (other than the infamous V-1)?
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They are....only DARPA at the moment is working with the Lockwood-Hiller design. Mine is much better...am still hoping to demo it for them. There's money involved. Drat!!!
Take a look at the wave corperation. Kevin
 

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KHambsch said:
They are....only DARPA at the moment is working with the Lockwood-Hiller design. Mine is much better...am still hoping to demo it for them. There's money involved. Drat!!!
Take a look at the wave corperation. Kevin
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I would like some of that chedder. My engine is only 8" in diameter and approx. the same length. Better SFC and improves with ram air.
 

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OliverSedlacek said:
Kevin, I don't think DARPA is going to be the sort of organisation that does 'low cost' anything. As a civilian I know nothing about how big a warhead is useful or how much it costs. 'Useful' range depends on geography, and at the top of my mind is the Ukraine invasion. If I get the time I may try and figure out some numbers to see what the pulse jet Vs turbojet costs look like.
I'm thinking 'Scrapheap challenge', not BAE Systems.
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2.85 million $
 

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KHambsch said:
So DARPA has dumped 3 million in on Lockwood-Hiller. I find this ludicrous....The SFC on the digitally controlled Lockwood is 2 where my design is = or < 1.
I attach the notional art work of the Lockwood-Hiller "aircraft" again to show lack of ram air pressure acceptance. Best, K
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Then how would your design work?
 
topspeed3 said:
Yes...there could be a gap between pulsejet and ram air scramjet ?
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I have a subsonic (quazi ramjet) engine that produces static thrust and improves performance as velocity increases. I supose it would be OK up to 1.8 M per the normal shock inlet, I wouldn't even think of going past .9 Mach....per all sorts of "stuff" starts happening.
: ) K
 
KHambsch said:
I have a subsonic (quazi ramjet) engine that produces static thrust and improves performance as velocity increases. I supose it would be OK up to 1.8 M per the normal shock inlet, I wouldn't even think of going past .9 Mach....per all sorts of "stuff" starts happening.
: ) K
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Of course supasonic aeromystics sorta reverses itself from subsonic brother.
 
KHambsch said:
I have a subsonic (quazi ramjet) engine that produces static thrust and improves performance as velocity increases. I supose it would be OK up to 1.8 M per the normal shock inlet, I wouldn't even think of going past .9 Mach....per all sorts of "stuff" starts happening.
: ) K
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Okay please help me to understand how your engine works.
 
KHambsch said:
A quick run down:
1 Axial design
2 Open forward facing intake
3 Supersonic, super heated fuel is used to induce ambient air into the combustor...
then
4 Expanding out the nozzle
Will post video on next hot fire test
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Interested in case it happens to have run!
 
KHambsch said:
A quick run down:
1 Axial design
2 Open forward facing intake
3 Supersonic, super heated fuel is used to induce ambient air into the combustor...
then
4 Expanding out the nozzle
Will post video on next hot fire test
Click to expand...
3. - SCRAM jet?
 
Scott Kenny said:
Yes and no. What DARPA wants is the capabilities. Usually that means expensive stuff to get what they want to do.

But if you demonstrate more range from a cheaper engine, they will be all over that because it has more range.
If you demonstrate equal range from a cheaper engine they might want it, depends on how many more units they can buy with the cheaper engine.
If you can't equal the range of the unit they're using, DARPA will hard pass, even if your engine is 1/10 the cost.
Click to expand...
DARPA doesn't do a bulk buys or production runs. It only deals with demonstrators. How many units "they" can buy is not a question they deal with. If a service wants a capability at a low cost, DARPA will look into it.
A service will look at something at a lower capability if it is substantially cheaper.
 
Byeman said:
DARPA doesn't do a bulk buys or production runs. It only deals with demonstrators. How many units "they" can buy is not a question they deal with. If a service wants a capability at a low cost, DARPA will look into it.
A service will look at something at a lower capability if it is substantially cheaper.
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Darpa has chosen the Lockwood-Hiller valveless pulsejet engine...(the "U" shaped one....better fuel consumption than usual because of a modern fuel injection system: 2lbsfuel/lbthrust/hour.
My design 1lbfuel/lbthrust/hr, more compact, advantaged by ram air which increases SFC.
No change in cost
 
KHambsch said:
Darpa has chosen the Lockwood-Hiller valveless pulsejet engine...(the "U" shaped one....better fuel consumption than usual because of a modern fuel injection system: 2lbsfuel/lbthrust/hour.
My design 1lbfuel/lbthrust/hr, more compact, advantaged by ram air which increases SFC.
No change in cost
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Okay, so if/when the program goes to a full bid, you have a good argument for using your design instead of the Lockwood-Hiller valveless design: double the range.
 
KHambsch said:
Darpa has chosen the Lockwood-Hiller valveless pulsejet engine...(the "U" shaped one....better fuel consumption than usual because of a modern fuel injection system: 2lbsfuel/lbthrust/hour.
My design 1lbfuel/lbthrust/hr, more compact, advantaged by ram air which increases SFC.
No change in cost
Click to expand...

Any news of the hot fire test you were mentionning in September?
 

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