Maximum Lift

QS RADICAL

150 mm height with 3 complete biomimetic patterns: leading-edge tubercles, trailing-edge serrations, and surface microchannels. NACA 6410 profile validated with OpenFOAM CFD (k-omega SST). Max CL of 0.3442, +385% vs FCS M-5. Additive manufacturing in 5 sizes with optional gyroid core.

RADICAL

vs FCS M-5

CFD comparison with OpenFOAM, simpleFoam solver (k-omega SST), V=7.5 m/s, coarse mesh. RADICAL v3 L (H=150 mm) vs FCS M-5 (H=115 mm, NACA 0012, rake 20deg, sweep 3deg). Same conditions for both fins.

Metric	RADICAL v3	FCS M-5	Improvement
Max CL	0.3442	0.0709	+385%
Max L/D	15.3	3.8	+303%
Lift at 15deg	148.8 N	36.6 N	+307%

Specifications

Geometry

Height 150 mm

Base (chord) 115 mm

Tip chord 57.5 mm

Rake 15deg

Sweep 5deg

Twist (cant) 0.0deg (no twist)

NACA profile 6410 (camber 6%, thickness 10%)

Surface area 305.1 cm2 (size L)

Tip chord ratio 0.5

Biomimetics Tubercles + Serrations + Microchannels

Material PA-CF + epoxy + carbon fiber

System FCS II

Best numbers

Max CL

CL of 0.3442 at 15deg angle of attack. +385% vs FCS M-5 (CL 0.0709). The NACA 6410 profile with 6% camber generates far higher lift than the symmetric 0012.

Max efficiency

L/D of 15.3 at 15deg, triple the FCS M-5 (L/D 3.8). Full biomimetics keep flow attached at high angles.

Early lift

104.2 N of lift at 5deg angle of attack. The FCS M-5 generates only 12.8 N under the same conditions. Camber + biomimetics produce far superior lift from low angles.

3 biomimetic patterns

Nature engineered in CFD

Each feature is parameterized, simulated and optimized for this fin. Not decoration -- individual performance contribution validated with CFD.

RADICAL biomimetic features: tubercles, serrations, microchannels

All 3 biomimetic patterns integrated into the geometry: leading-edge tubercles (Megaptera), trailing-edge serrations (Bubo) and surface microchannels (Carcharodon).

LE Tubercles

Megaptera novaeangliae

Amplitude 4.0 mm, 5 cycles on the leading edge. Delay stall and improve control at high angles of attack. Parameterized sinusoidal pattern.

TE Serrations

Bubo virginianus

Amplitude 6.0 mm, 6 cycles on the trailing edge. Reduce hydrodynamic noise and improve wake efficiency. Sawtooth pattern.

Microchannels

Carcharodon carcharias

Amplitude 0.5 mm, 8 channels per side. Reduce skin friction in turbulent flow. Longitudinal microchannels aligned with flow.

CFD

OpenFOAM simulation

CFD with OpenFOAM, simpleFoam solver (k-omega SST), coarse mesh. Fluid: saltwater at 7.5 m/s. Direct comparison RADICAL v3 L vs FCS M-5 under identical conditions.

RADICAL CFD simulation -- lift and drag curves by angle of attack

RADICAL v3 L (H=150, B=115, NACA 6410, rake 15deg, sweep 5deg)

Angle	Lift (N)	Drag (N)	CL	CD	L/D	vs M5 Lift	vs M5 L/D
5deg	104.2	13.2	0.2409	0.0305	7.9	+714%	+229%
10deg	120.9	10.6	0.2795	0.0245	11.4	+408%	+256%
15deg	148.8	9.7	0.3442	0.0225	15.3	+307%	+303%

FCS M-5 reference (H=115, B=110, NACA 0012, rake 20deg, sweep 3deg)

Angle	Lift (N)	Drag (N)	CL	CD	L/D
5deg	12.8	5.3	0.0247	0.0102	2.4
10deg	23.8	7.5	0.0461	0.0145	3.2
15deg	36.6	9.7	0.0709	0.0188	3.8

CL max RADICAL v3: 0.3442 vs M5: 0.0709 -- +385%. L/D max RADICAL v3: 15.3 vs M5: 3.8 -- +303%. Promising results. Pending: validation with medium mesh and fine CFD.

CFD RADICAL -- wake visualization and pressure distribution

Manufacturing

Additive manufacturing

3D printed in PA-CF (carbon-fiber nylon) or PETG. Optional epoxy + carbon fiber layup (200 g/m2, 2 layers per side). Optional TPMS gyroid core for weight reduction. Complete thruster set (R/L/C) with tactile marking on FCS II tab.

Size	Height (mm)	Base (mm)	Thickness (mm)	Area (cm2)	Core vol (cm3)	PETG (g)	PA-CF (g)	PETG +layup (g)	PA-CF +layup (g)
S	125	138.3	22.24	231.25	57.41	72.9	70.0	90.8	88.0
M	140	152.6	24.79	288.65	82.01	104.1	100.0	126.5	122.4
L	150	152.9	25.67	305.12	87.20	110.7	106.4	134.4	130.0
XL	170	182.8	32.07	397.57	132.71	168.5	161.9	199.4	192.7
XXL	185	200.4	34.81	473.25	173.53	220.4	211.7	257.1	248.4

Base = total span including FCS II box + NACA fillet. PETG: 1.27 g/cm3, PA-CF: 1.22 g/cm3. Layup: +0.5 mm epoxy + carbon fiber at 1.55 g/cm3 (200 g/m2, 2 layers per side). Optional TPMS gyroid core: -30% to -40% weight.

Full methodology