If More WWII Fighters Had Laminar Flow Wings

[Reverie Planetarian]

A little thought experiment, if I may:

I forget if the Mustang was the only US WWII fighter to play with a laminar flow wing shape but I know it was part of its success with regards to its performance.

Assuming it was the first or only to try it out, I wonder if it would've helped other aircraft of the time? Could you, for example, make a P-38 Lightning with vastly improved performance assuming you advanced its engine to about the same needs, also assuming the need for much faster heavy fighters and piston aircraft were suitably high? Or, perhaps, would jet technology have rendered this particular part of aerodynamics research a secondary goal, or more likely, used a more aggressive research of wing cross-sections and smooth airflow to further its own goals?

 

[riggerrob]

The B-24 Liberator bomber used a Davis airfoil section that maintained laminar flow similar to the P-51. Liberator also had a much-heavier wing-loading (than its B-17 stablemate) making the Liberator more efficient in cruise, but also more challenging during take-off.
Laminar airfoils are only part if the drag reduction equation.
Secondly, laminar airfoils need precise construction (flush rivets, butt joints between skin panels, etc.). To maintain laminar flow. Cleaning and even re painting can ruin laminar flow, because even a few dead insects can trip laminar flow.
Thirdly, ALL the exterior components need to be optimized for laminar flow, including all the intersections and fairings. For example, over the last decade, most of the refinements to business jets have involved subtle changes to airflow around intersections like wing roots and engine nacelles.

 

[Aeroweanie]

The Bell P-63 Kingcobra, Lockheed P-80, Douglas A-26 Invader, Hawker Tempest and Supermarine Spiteful all had wings incorporating laminar flow airfoils. As Riggerrob noted, the Consolidated XP4Y Corregidor, B-24 Liberator and B-32 Dominator wings incorporated a Davis airfoil that was a laminar flow airfoil, although the designer (David Davis) didn't know this.

 

[Foo Fighter]

With the P-51, I think the overall drag had a bigger effect and the radiator design too.

 

[Aeroweanie]

NACA data shows that operationally, the laminar flow airfoils didn't provide much drag reduction, due to premature flow transition. My assessment is that the low drag came primarily rom the cooling system.

 

[tomo pauk]

Assuming it was the first or only to try it out, I wonder if it would've helped other aircraft of the time? Could you, for example, make a P-38 Lightning with vastly improved performance assuming you advanced its engine to about the same needs, also assuming the need for much faster heavy fighters and piston aircraft were suitably high

Better late than never, I guess
P-38 would've been the greatest beneficiary. NACA tested one YP-38 with different airfoils between the pod and the engines in order to cure the compressibility problems, the laminar flow wing section was one of things that helped out.
Typhoon, Beaufighter, A-20 - aircraft with potential for better speed figures, but wing choice was not conductive to that - would've also benefited.
Spitfire - not so much, wing was already of low drag. Hurricane would've benefitted more IMO.

 

[riggerrob]

Assuming it was the first or only to try it out, I wonder if it would've helped other aircraft of the time? Could you, for example, make a P-38 Lightning with vastly improved performance assuming you advanced its engine to about the same needs, also assuming the need for much faster heavy fighters and piston aircraft were suitably high

Better late than never, I guess
P-38 would've been the greatest beneficiary. NACA tested one YP-38 with different airfoils between the pod and the engines in order to cure the compressibility problems, the laminar flow wing section was one of things that helped out.
Typhoon, Beaufighter, A-20 - aircraft with potential for better speed figures, but wing choice was not conductive to that - would've also benefited.
Spitfire - not so much, wing was already of low drag. Hurricane would've benefitted more IMO.

If you want to understand how much a laminar wing might have improved Hawker Hurricane performance .... compare the thick-winged Hawker Typhoon with the laminar-winged Tempest. Tempest was essentially a de-bugged Typhoon fuselage with an entirely new wing that featured both laminar airfoil sections and an elliptical planform.
Typhoon Mark Ib had a top speed of 412 miles per hour, while Tempest topped 435 mph.
Typhoon and Tempest eventually evolved into the Hawker Sea Fury which was the ultimate British prop-driven fighter, serving well into the 1950s with a dozen smaller air forces (e.g. Cuba). Modified Sea Furies own many races during the Remo Air Races in 2022.