Author Topic: Avro CF-100 Variants  (Read 1154 times)

Offline tankmodeler

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Re: Avro CF-100 Variants
« Reply #15 on: August 02, 2018, 09:11:51 AM »
Well, for night/bad weather operations, I could see the second crewman being very useful, particularly if suitable sensor fit was made.
The CF-100 was a dedicated night/all weather interceptor. The second crewman operated the state of the art collision course intercept system and radar.

In the twilight of its career the last operational Clunks were flown by 414 Sqdn who were an Electronic warfare squadron which, in peacetime, were tasked with simulating enemy attacks on North America to exercise NORAD while pretending to be Bears and Blinders. A lot of US and Canadian cities were "bombed" by these aircraft when they managed to elude or spoof the defending NORAD fighters.

Online finsrin

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Re: Avro CF-100 Variants
« Reply #16 on: August 03, 2018, 04:10:07 PM »
Extended wing recon version is nifty.

Offline kitnut617

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Re: Avro CF-100 Variants
« Reply #17 on: August 04, 2018, 11:04:45 PM »
Thanks Bill ---

The nice thing about using the Mk.5 wing is that the bottom part (yes it has two parts even though the wing is ultra thin) has an extension for the four foot wing extension moulded in. I'm going to use it to support my even longer extension top part and then cut a slot into the bottom half of my extension to suit it. My extension adds another seven feet to the wing tips of each wing, that's over and above the four feet the Mk.5 had..
« Last Edit: August 04, 2018, 11:06:24 PM by kitnut617 »

Offline tankmodeler

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Re: Avro CF-100 Variants
« Reply #18 on: August 14, 2018, 01:12:33 AM »
With the fan nacelle modifications it certainly looks like a Canadian RB-57 Canberra/Clunk cross, doesn't it?

Offline kitnut617

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Re: Avro CF-100 Variants
« Reply #19 on: August 14, 2018, 07:56:31 AM »
With the fan nacelle modifications it certainly looks like a Canadian RB-57 Canberra/Clunk cross, doesn't it?

Well I have an RB-57F build ongoing ---- It did give me the idea for this one, especially after I had moved the engine nacelles outwards so I could fit the recon pannier between the u/c bays. Just seemed a natural progression --- 

Offline tankmodeler

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Re: Avro CF-100 Variants
« Reply #20 on: August 14, 2018, 11:32:56 PM »
Just seemed a natural progression ---
Yep, certainly does.

Producing a TF-33 -like turbofan version of the Canuck's Orenda engine could easily have seen the thrust increase from the 7400 lbf of the Orenda-9, dry, to something like 11,000 lbf, dry, an exceptionally healthy increase, along with an increase in range as well.

Perfect for a recce version, as you show, and also useful if the wings were strengthened and the aircraft turned into a single-seater bomb truck. Actually, if the second seat was retained and precision bombing aids added, it could have been a precision strike aircraft along the lines of the A-6 or Buccaneer. That would have been cool to see in Europe in the early 60s in the grey/green camo pattern, no?

I think I've got a Clunk in the stash somewhere...

Paul

Offline elmayerle

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Re: Avro CF-100 Variants
« Reply #21 on: August 17, 2018, 12:41:43 PM »
How easy the Orenda could be converted to a turbofan is another question.  If it's a single-spool engine, it's going to be difficult without adding another spool (much like what GE did in converting the CJ610 to the CF700).  If it was a twin-spool engine, the conversion is much simpler, involving a redesign of the first few compressor stages to fans (JT3C --> JT3D, JT8B (J52) --> JT8D, etc.).  Not trying to throw cold water on the idea, just pointing a few things out.  Perhaps use an intermediate stage between Orenda and Iroquois that fits the Orenda envelope, but is twin-spool, as a basis for the turbofan; it could've been a proof-of-concept effort that went into production.

Offline kitnut617

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Re: Avro CF-100 Variants
« Reply #22 on: August 17, 2018, 08:21:00 PM »
For my project the idea is in typical Canadian Government fashion, something was 'picked-off-the-shelf'   :P  Of course it took years to develop    ;D ;D ;D

Offline tankmodeler

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Re: Avro CF-100 Variants
« Reply #23 on: August 18, 2018, 01:29:06 AM »
How easy the Orenda could be converted to a turbofan is another question.  If it's a single-spool engine
It was, indeed, a single spool engine. And, yes, it's really not possible to convert it to a turbofan without adding a second spool, the mass flow and speed requirements pretty much demand a second spool.

As a WHIF, we can imagine that after the Orenda 11 a new engine was created that used many Orenda parts and stages, but was designed around 2 spools and was a forward-mounted, low bypass turbofan.

In a more real-life game of what if, one could take an Orenda engine and do what GE did for the J-79, add a separate fan and turbine stage at the back of the engine, "simply" lengthening the whole thing by the added turbine stages and fan stage. This does work and was in service on the Convair 990 with CJ805-23 engines.

For the model it would reverse the short fan cowl, putting it at the aft end of the engine.

Paul

Offline apophenia

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Re: Avro CF-100 Variants
« Reply #24 on: August 18, 2018, 07:18:02 AM »
What about shifting to the two-spool Orenda PS.13 Iroquois for the basis for your turbofan derivative? Diameters for the Iroquois and Orenda 14 are the same - 42 inches.
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Offline elmayerle

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Re: Avro CF-100 Variants
« Reply #25 on: August 18, 2018, 11:26:26 AM »
How easy the Orenda could be converted to a turbofan is another question.  If it's a single-spool engine
It was, indeed, a single spool engine. And, yes, it's really not possible to convert it to a turbofan without adding a second spool, the mass flow and speed requirements pretty much demand a second spool.

As a WHIF, we can imagine that after the Orenda 11 a new engine was created that used many Orenda parts and stages, but was designed around 2 spools and was a forward-mounted, low bypass turbofan.

In a more real-life game of what if, one could take an Orenda engine and do what GE did for the J-79, add a separate fan and turbine stage at the back of the engine, "simply" lengthening the whole thing by the added turbine stages and fan stage. This does work and was in service on the Convair 990 with CJ805-23 engines.

For the model it would reverse the short fan cowl, putting it at the aft end of the engine.

Paul
That could be done, but I admit to still being partial to my idea of an intermediate stage between Orenda and Iroquois that initially served as a two-spool testbed and was later put into production for "special" CF-100 variants and other special projects.  Basically the Orenda 11 that tankmodeler described.  I could see a later variant of the high-altitude CF-100 getting powered by a dry turbofan version of the Iroquois (after all, P&W did scheme, and did component testing on, a JT4D turbofan version of the J75; just never got any sales so didn't build any).

Offline kitnut617

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Re: Avro CF-100 Variants
« Reply #26 on: August 20, 2018, 06:51:05 AM »
How easy the Orenda could be converted to a turbofan is another question.  If it's a single-spool engine
It was, indeed, a single spool engine. And, yes, it's really not possible to convert it to a turbofan without adding a second spool, the mass flow and speed requirements pretty much demand a second spool.

As a WHIF, we can imagine that after the Orenda 11 a new engine was created that used many Orenda parts and stages, but was designed around 2 spools and was a forward-mounted, low bypass turbofan.

In a more real-life game of what if, one could take an Orenda engine and do what GE did for the J-79, add a separate fan and turbine stage at the back of the engine, "simply" lengthening the whole thing by the added turbine stages and fan stage. This does work and was in service on the Convair 990 with CJ805-23 engines.

For the model it would reverse the short fan cowl, putting it at the aft end of the engine.

Paul
That could be done, but I admit to still being partial to my idea of an intermediate stage between Orenda and Iroquois that initially served as a two-spool testbed and was later put into production for "special" CF-100 variants and other special projects.  Basically the Orenda 11 that tankmodeler described.  I could see a later variant of the high-altitude CF-100 getting powered by a dry turbofan version of the Iroquois (after all, P&W did scheme, and did component testing on, a JT4D turbofan version of the J75; just never got any sales so didn't build any).

Interesting twist to the thread this, because for my Avro Atlantic which in my alt-history world, was built by Avro Canada for Avro GB and also supplied it to the RCAF as the CC-137 Husky instead of the Boeing 707. My story has it powered by four Iroquois without afterburners.  This could fit in here.
« Last Edit: August 20, 2018, 07:06:13 AM by kitnut617 »

Offline tankmodeler

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Re: Avro CF-100 Variants
« Reply #27 on: August 20, 2018, 11:17:16 PM »
What about shifting to the two-spool Orenda PS.13 Iroquois for the basis for your turbofan derivative? Diameters for the Iroquois and Orenda 14 are the same - 42 inches.
I suspect an Iroquois turbofan would be vastly overpowering for a CF-100 airframe, no matter what you did to strengthen it. At 19,350 lbf dry, it's got 3 times the dry thrust of an Orenda 9. A fan would likely increase thrust above that with no reheat, just like the JT-3 to JT-3D which went from ~11k lbf to ~17K lbf with the addition of the low bypass fan.

The 2 spool "scaled down" Iroquois concept turned into a low bypass turbofan would very likely have been the development route, not unlike several P&W engines of the late 50s. If it ended up around 15-16k lbf thrust you'd have a very robust military turbofan a little smaller than the Yank TF-33 and pretty suitable for a Clunk-sized bomb truck or longer ranged recce bird.

Paul