Blohm & Voss Bv.155

In September 1943 the Reich's Air Ministry placed an order for five prototypes which was accepted by Blohm & Voss under the condition of having complete design freedom and not being bound by Messerschmitt's work to date. The redesign received the name of Bv.155 and received a new laminar flow, wing and tail unit, lading gear from the Junkers Ju.87 and many other parts of the plane. This first early redesign was known as the Bv.155A and it vaguely resembled the Bf.109K. It never went beyond the wind testing tunnel model as it was shown that overwing radiators (one of the features of the new redesign) created some serious problems at high angles of attack as the wing "blanked" them from the airflow and cooling would suffer so the model was abandoned with just one testing model having been built.
The revised B model went much further ahead and its first prototype, named V1 took off on 1st September 1944. When testing the V1 it was shown that the outboard radiators provided inadequate cooling, specially at high attack angles, just like with the wind tunnel model of the A variant so the intakes in the second prototype, V2, were enlarged and underslung beneath the wing instead of placing them over the wing. This changement, however, changed the aircraft's centre of gravity requiring the pressurized cockpit to be moved forward. The Blohm & Voss team took advantage of this problem to replace Messerschmitt's original cockpit with another aft-sliding all-round vision of their own and to cut down the rear fuselage decking. This required a larger rudder to be fitted as well as a new ventral enlarged radiator bath.
After all these changes, the Bv.155 V2 flew for the first time on 8th February 1945, but Blohm & Voss was still not satisfied with the design and, before the trials begun, they had proposed to switch the engine to the DB 603U having the larger mechanically driven supercharger of the DB 603E. The DB 603U promised a power of 1660 hp for taking off and 1430 hp at 14935 m (49000 ft) high. The ventral turbosupercharger was retained. The Technisches Amt accepted this new proposal and abandoned all work on the Bv.155B in favour of the revised design which was called Bv.155C.
The Bv.155V2 was damaged beyond repair due to a bad landing and was to be replaced by a third prototype, the Bv.155V3, which was fitted with the DB 603U intended for the Bv.155C, however, both the engine cowling and turbosupercharger were unchanged.
Various armament proposals were made for the Bv.155B. The first one had an engine-mounted 30mm Mk.108 cannon and two 20mm MG 151/20 cannons mounted on the engine cowling.
The second one had a 30 mm Mk.103 cannon mounted in the engine and two wing-mounted 20 mm MG 151 cannons. The third had three 30 mm Mk.108, one of them engine-mounted and the other two in the cowling and the fourth one was identical to the third one but with two Mk.108 mounted in the wing instead of the cowling.
Estimated maximum speed was 650 km/h (400 mph) at 12.000 m (52490 ft) with a service ceiling of 16950 m (55610 ft) high. According to some sources, both V1 and V2 were provided to the Royal Air Force after the war, which tested them until they were written off and V3 lies in storage at the US Air and Space's museum storage.
In parallel with the prototype development, Blohm & Voss had been working on additional changes under the name of Project 205. Project 205 (P.205) replaced the underwing radiators with an annular one around the front of the engine, a very common design feature found in many German designs of the time. With the wings free of clutter, they were considerably simpler and reduced in span. This also had the side effect of reducing the track , which turned to be a welcome change. The new design was going to be simpler, lighter and faster and it was planned to be the standard version of the aircraft. During October's re-evaluation, it was agreed that V1 to V3 were going to be completed to B standards, while a new series of five were going to be completed to the new standard as the Bv.155C. However, as with many other projects, the initial design (which we drawn) suffered many changes.
The Bv.155C was to be different from the Bv.155B. The wing mounted radiators were eliminated, and the main landing gear leg attachments were moved inboard to retract inwards. Cooling was provided by an anular frontal radiator just like the Focke-Wulf Ta.152. Large circular intakes were attached to the fuselage sides above the wing roots.

Sources:
1. https://en.wikipedia.org/wiki/Blohm_%26_Voss_BV_155
2. Salamander Books - The Complete Book of Fighters
3. Monogram Close up 20 - Blohm & Voss BV155