Author Topic: Apophenia's Offerings  (Read 308207 times)

Offline Brian da Basher

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Re: Apophenia's Offerings
« Reply #2100 on: March 31, 2019, 05:27:35 PM »
It takes a keen eye and buckets of talent to render engine detail like that!

Great stuff, apophenia!

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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2101 on: April 02, 2019, 02:23:17 AM »
Thanks Brian ... I don't seem to be able to resist those under-the-hood-gubbins  ;)

'Ragazzo di Corso' - The Fiat V-16-Powered Macchi 'C.204/A.38' Project

By the summer of 1939, ing. Mario Castoldi was considering a planned Fiat V-16 engine as a potential powerplant for the Macchi C.204. In its original iteration, this Fiat A.38 engine was an upright V-16 related to the 1939 Fiat AS.8 racing engine. To produce the A.38, Fiat's ing. Tranquillo Zerbi had simplified his AS.8 racing engine. Compared with the AS.8, the A.38 had a revised bore and stroke [1] as well as a much lower compression ratio.

The adaptation of the Macchi airframe was not a simple one due to the length of the Fiat engine. However, such an installation appeared achievable with some re-arrangement of internal equipment. Although long, the new Fiat A.38 engine was compact in height and width compared with the existing Isotta-Fraschini Asso L.121 V-12 which was also being considered for the Macchi C.204.

The so-called 'C.204/A.38' first appeared in early May 1939 Aer.Macchi drawings. These revealed considerable deviations from the contemporary 'C.204/L.121' concept. Whereas the latter was essentially a C.202 airframe with different engine mounts and cowling for the Asso L.121 engine, the longer Fiat V-16 required the firewall to be moved aft. This was feasible because the compact frontal area of the A.38 allowed this engine to sit atop the undercarriage wheel bays and wing structure. Castoldi believed that, with the engine set as far back as possible, manoeuvrability would be as good as - if not better than - the C.202 Folgore.

Despite the aft-positioned engine, it quickly became apparent that nose-heaviness was going to be an issue. For 'Fase di progettazione Ia' ('Design Phase Ia'), notional work was begun on redressing that nascent imbalance. An obvious start was moving the convenient but drag-inducing under-engine radiator bath aft to below the rear fuselage. A more radical possibility was to lengthen the rear fuselage itself. If necessary, it was considered reasonable to enact both changes. Some design work was also begun on armament options - since cowl-guns were not practical in the 'C.204/A.38' design.

Unfortunately, the 'C.204/A.38' never had a chance to prove its mettle. By July 1939, Fiat Motori [2] had abandoned the complex and weighty reduction gearbox for contra-rotating propellers. The A.38 R.C.42 would, instead, drive a 3-bladed variable-pitch propeller. This raised concerns as to whether the C.204 airframe's tail was large enough to deal with 'propeller torque'. That was a moot point. Before design work could be completed on the 'C.204/A.38 FdP Ia', Fiat Motori advised the Varese design office that work was being discontinued on the upright A.38 engine. In the absence of a viable Fiat rival, the 'C.204/L.121' was the model which would see production and active service with the Regia Aeronautica.

(To be continued ...)
_______________________________

[1] The AS.8 racing engine had a 'square' bore and stroke of 140 x 140mm. Bore and stroke dimensions for the A.38 fighter engine was 138 x 145 mm.

[2] In its full form, S.A. Fiat Motori d'Aviazione. Fiat Motori had facilities at Torino and Firenze.
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Offline Brian da Basher

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Re: Apophenia's Offerings
« Reply #2102 on: April 02, 2019, 06:16:12 AM »
Contra-props and an Art-Deco style cowling for teh win!!!

Great stuff, apophenia and oddly prescient as I was just looking at how well an He-51 engine works on a Veltro.

Brain da Basher

Offline apophenia

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Re: Apophenia's Offerings
« Reply #2103 on: April 04, 2019, 04:25:24 AM »
Cheers Brian. A little more conventional on the cowling this time ...

Topsy-Turvy - the Upsidedown Fiat A.38 IV-16 Engine

Fiat Motori's work on the A.38 engine was not abandoned completely. Instead, ing. Antonio Fessia and Carlo Bona undertook a complete revision of the new Fiat engine. This major redesign was need to meet a new-found Regia Aeronautica's sudden preference for invertita aero-engines for fighters. In its early 1940 form, the A.38 was duly inverted and had its potential for contra-rotating propellers restored. In the absence of detailed information, the Varese design office planned for a simple 'inversion' of the original, upright A.38.

For a straighforward 'inversion' of the original Fiat V-16 engine, some assumptions from the 'C.204/A.38' Fase di progettazione Ia would hold. The thrust-line would, of course be lower but only slightly since the smaller-frontal-area engine would be mounted a little higher in the airframe. To ensure ground clearance, it seemed safe to assume smaller-diameter 3-bladed propellers. The contra-props would also answer Aer.Macchi concerns about 'propeller torque' and suggested that the tailplane inherited from the C.200 would continue to be adequate.

With its revised 'motore invertito', the 'C.204/A.38' became the 'C.202/A.38'. This incorporated the planned revisions to the 'C.204/A.38' design - including the rearward movement of the radiator bath. For a prototype 'C.202/A.38', it was thought that re-arrangement of C.202 internal equipment and some lead counter-weights would be sufficient to balance its centre-of-gravity. For a production 'C.202/A.38', a lengthened rear fuselage was planned to offset the weight of the lengthy Fiat IV-16 engine. Alas, all this planning at Varese went out the window when Fiat Motori announced another design change.

For the production-model A.38, the supercharger was to be relocated to reduce overall length. Rather than have the supercharger directly behind the engine block, this compressor was now to be mounted below the hindmost cylinder heads. [1] Such an arrangement would greatly complicated supercharger drive but Fessia and Bona thought this worthwhile to reduce length. Unfortunately for Aer.Macchi, that bulky supercharger and its air intakes would now be located precisely where the main undercarriage wheels of the C.202 were housed when retracted. In its late Spring 1940 form, the Fiat A.38 engine could simply not be fitted to the C.202 airframe without a massive redesign effort.

Top Fase di Progettazione II 'C.202/A.38' project as envisioned at the prototype stage. Note original, 'short' C.202-style rear fuselage.

Bottom 'C.202/A.38' project as envisioned as an in-service production machine. The rear fuselage has been lengthened but no conclusions had yet been drawn about how the Fiat-powered fighter was to be armed.

(To be continued ...)

_______________________________

[1] It was also revealed that the 2-bladed propellers were being retained. Although not as critical as the relocated supercharger, the longer prop blades raised questions about ground clearance. Would the original C.200-style undercarriage legs be long enough?
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Offline Brian da Basher

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Re: Apophenia's Offerings
« Reply #2104 on: April 04, 2019, 05:00:07 AM »
Now that's sweeet! Love the contra-props and you went with the perfect color scheme on the bottom one!

A feast for the eyes!

Brian da Basher

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Re: Apophenia's Offerings
« Reply #2105 on: April 05, 2019, 01:22:49 AM »
One of those would look good as a floatplane racer. ;)
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Offline elmayerle

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Re: Apophenia's Offerings
« Reply #2106 on: April 05, 2019, 11:17:39 AM »
Beautiful renderings and great story!!  Be most interesting to watch the continued evolution here.  I can't help but wonder if we might see a single jet engine-powered version, something analogous to the Yak-15.

Offline apophenia

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Re: Apophenia's Offerings
« Reply #2107 on: April 06, 2019, 06:55:39 AM »
Thanks folks. I've been pondering something Jumo-powered as well Evan - but haven't settled on anything yet.  Meanwhile ...
_______________________________

'Programma di Pinocchio' - The Macchi C.222 Progetta

For ing. Mario Castoldi, the 'C.202/A.38' was the breaking point for the ever-changing Fiat IV-16 engine. All remaining A.38 design work was fobbed off on ing. Ermanno Bazzocchi, Castoldi's assistant. Bazzocchi recognized that a larger airframe was necessary. Only by greatly stretching the C.202 fuselage, could it possibly accommodate the Fiat A.38 with its underslung supercharger. With the resulting structural weight gain, enlarging the wing area also became essential.

To increase wing area, ing. Bazzocchi came up with a comparatively simple solution. A new centre section would be inserted beneath the fuselage. The existing C.202 wing would then be attached to this new centre section as outer wing panels. The fuselage used many basic C.202 individual components but, in finished form, was much lengthened. Two fuselage forms were proposed. For Fase di progettazione (Design Phase) IVa, the cockpit was maintained in the C.202 position to maximize pilot visibility. Synchronization gear would be devised in order to fire twin 12.7 mm Breda-SAFAT guns through the contra-rotating propellers.

For Fase di progettazione IVb, the cockpit was moved aft (a part of the fuselage stretch being in front of 'the office'). The purpose of the FdP IVb arrangement was to accommodate a pair of syncrhronized 20 mm MG151/20 cannons in place of the Breda-SAFAT cowl guns. Consideration was also given to incorporating a sliding canopy to improve pilot view on take-off and landing. But, otherwise, Fase di progettazione IVb was identical to FdP IVa. As the latter represented less development time, a prototype was ordered under the new designation - Macchi C.222.

The prototype C.222 was constructed at Varese using as many C.202 parts and components as possible. Work on this prototype progressed at a rather leisurely pace since Fiat Motori was yet to produce a flight-worthy A.38 powerplant. In the interim, a 'dummy' engine was installed to finalize anciliary equipment placement. In the meantime, design work continued at Varese on other A.38-powered Macchi fighters. The Fase di progettazione V was similar to the FdP IVb concept but incorporated an entirely new wing. As with the earlier phases, the FdP V had a separate centre-section but the outer panels were new. These panels were of similar outline to the C.202 originals but had a broader chord for increased wing area.

Intercettore a Potenza Mista - Bazzocchi's Mixed-Power Interceptor

The Fase di progettazione V was not pursued but it led directly to the FdP VII - a mixed-power concept interceptor. [1] This aircraft retained the Fiat A.38 but this engine was to be modified with a power take-off at its rear. An extension shaft would then drive a motore a reazione devised by another Milanese firm, Tecnomasio Italiano-Brown Boveri. This TIBB MG (for Motore Getto) would be ignited for take-off and climb before being disengaged with an extension shaft clutch. The TIBB MG was dubbed a motorjet to distinguish it from similar work being done by Secondo Campini. [2]

Much to Mario Castoldi's chagrin, the FdP VII concept was assigned the working designation MB.222MG, with the suffix honouring the work of ing. Bazzocchi. From the cockpit forward, the MB.222MG strongly resembled the FdP V. However, the rear fuselage was changed utterly. Traditionally shapely Macchi lines gave way to a portly fuselage with side air intakes to feed the TIBB MG powerplant. To ensure stability, Castoldi's elegant tailplane design was replaced by twin fins.

It was envisioned that the MB.222MG would retain the FdP V's planned wing armament of four 20 mm cannons but cowl guns were dispensed with to save weight. Annular kerosene fuel tanks for the TIBB MG surrounded that powerplant and consideration was given to carrying additional fuel in wing-mounted drop tanks. The result was intended to provide a fast-climbing but relatively short-range interceptor to counter Allied bombers in Italian skies. As with the more conventional Macchi C.222, the MB.222MG ran up against Fiat Motori's inability to deliver a single functioning A.38 engine - let alone one fitted with a rear power take-off for an extension shaft.

Both 'caccia 222' projects limped along in the hope than Fiat Motori might follow through on a promised A.38 replacement. [3] That never happened and both interceptor projects stalled. Perhaps appropriately, both the incomplete C.222 airframe in storage and all 'caccia 222' drawings and calculations were destroyed in the Allied bombing raid Macchi's Varese works of 01 May 1944.

_____________________________

[1] The Fase di progettazione VI was to have been an extended-span, high-altitude variant of the FdP V interceptor.

[2] More on how this TIBB powerplant came to be in the next post.

[3] The 47.6 litre A.48 R.C.20-60-I Burrasca (Gale) IV-16 was to be based upon Fiat Motori's license-built DB 605 - being effectively an RA.1050 RC.58-I Tifone with four extra cylinders. The overall failure of the A.38 programme aslo put paid to another Macchi project - the twin-engined C.301.
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Offline elmayerle

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Re: Apophenia's Offerings
« Reply #2108 on: April 06, 2019, 10:31:07 AM »
Unique whiffs and most interesting ones; certainly some tempting possibilities.   That's beautiful "smoke ring" camouflage, too; you're a real artist with that.

Offline ptdockyard

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Re: Apophenia's Offerings
« Reply #2109 on: April 06, 2019, 09:19:10 PM »
I am getting to the party late here...would love to see more Italian carrier planes like whffs of the Fiat G50bis A/N, Fiat 201 and Fiat G57.




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Re: Apophenia's Offerings
« Reply #2110 on: April 07, 2019, 04:32:40 AM »
I'm with you there.
All hail the God of Frustration!!!

Offline Hardrada55

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Re: Apophenia's Offerings
« Reply #2111 on: April 07, 2019, 08:46:18 AM »
me too!

Offline jcf

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Re: Apophenia's Offerings
« Reply #2112 on: April 08, 2019, 05:00:25 AM »
C.204/A38 front end reminds me of the unbuilt, V-16 powered Rider-Miller:


More here:
http://beyondthesprues.com/Forum/index.php?topic=3909.msg60639#msg60639
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2113 on: April 09, 2019, 04:16:20 AM »
C.204/A38 front end reminds me of the unbuilt, V-16 powered Rider-Miller:


Someday, a 'Keith Rider Fighter' just has to be whiffed out of that unbuilt beauty!

And for those who haven't read Jon's Harry Miller's V-16s ... thread yet, it is highly recommended  :smiley:

http://beyondthesprues.com/Forum/index.php?topic=3909.0
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Offline apophenia

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Re: Apophenia's Offerings
« Reply #2114 on: April 11, 2019, 05:37:39 AM »
Playing with turbogetti Macchi fighters...

While designing the mixed-power Macchi MB.222MG, ing. Ermanno Bazzocchi was informed of work progressing on autonomously-powered turbogetti concepts. Tecnomasio Italiano-Brown Boveri was quite aware of the limitations of its TIBB MG motore getto powerplant. Through its BBC Mannheim subsidiary, it was also reasonably well informed about German progress on genuine turbojet engines. TIBB's first domestic turbojet concept - the TIBB TG.1 - was a conservative, centrifugal-compressor type.

The TIBB TG.1 was designed more as a booster engine for use on existing piston-engined aircraft. Despite that, the Varese design office draughted a purely jet-powered derivative of the Macchi C.202. The C.202/TG.1 replaced the piston engine with two diminutive TIBB TG.1 jets mounted side-by-side in the nose. Each jet exhaust was to vent alongside the fuselage. The horizontal tailplane was raised halfway up a revised tail fin to clear the jet efflux. Otherwise few changes were envisioned to the C.202 airframe. Armament was to be 2 (or 4) 12.7 mm cowl guns plus a central heavy-calibre cannon. The latter weapon was in an early design stage but calibre was being narrowed down to 25 mm and 40 mm.

Top Macchi C.202/TG.1 'Folgetti' concept, 2 x TIBB TG.1 turbojets, armed here with twin 12.7 mm cowl guns and a short-barrelled Breda-SAFAT 25 mm

When the C.202/TG.1 concept was viewed by officials from Guidonia and from TIBB itself, a number of flaws were revealed. Centro sperimentali weapons experts voiced concern about muzzle blast from the heavy gun being vented so close to the engine air intake. TIBB engineers concerred but were more worried about the effects of the jet efflux so close to the cockpit. Resonance effects on the aluminium airframe from the jet exhaust were also seen as an issue. All of this became of purely academic interest when Macchi was informed that Tecnomasio Italiano-Brown Boveri had begun work on a much more powerful turbojet - the TIBB TG.4.

The C.202/TG.1 concept was quickly abandoned in favour of a new C.202/TG.4 design. That designation was probably something of a misnomer since, other than the wings, little would remain of the original C.202 airframe. Instead, ing. Bazzocchi took the MB.222MG as his starting point. Basically, the axial-compressor TIBB TG.4 engine would be installed in the MB.222MG rear fuselage. Without a piston engine in the nose, the rest of the airframe could be scaled-down. 'Long' and 'short' nosed versions were planned - the short-nosed mounting a heavy-calibre cannon, the long-nose housing up to eight 12.7 mm machine guns or five 20 mm MG 151/20 cannons.

On review, the C.202/TG.4 concept was given high marks by TIBB engineers. However, experience with the Campini-Caproni C.C.2 showed Guidonia officials the downsides of 'tail-dragger' jet airplanes. That, and the amount of airframe redesign required, put paid to the C.202/TG.4 concept.

Bottom Macchi C.202/TG.4 concept in 'short-nosed' form. 1 x TIBB TG.4 turbojet, armed here with twin 12.7 mm cowl guns and a long-barrelled Scotti 25 mm autocannon.

(To be continued ...)
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