Testing Vortex Generators in Flight — Stall Speed Drop & Real-World CFD Results

Today we’re flight-testing new vortex generators (VGs) and comparing real-world stall performance against CFD (computational fluid dynamics) predictions. We’ll test stall speeds clean and with flaps, evaluate handling, and dive into the CFD data that guided VG placement — down to the thousandth of an inch.

The goal: confirm how much lift, drag, and stability change after adding properly positioned VGs to a high-lift laminar wing.

This flight shows real stall behavior, recovery altitude, and in-flight calibration of the Garmin attitude indicator, followed by a detailed post-flight CFD analysis explaining why the changes work.

Timestamps:
00:00 – Takeoff & Overview
Testing new VGs installed on the wing; climb to 5,000 ft AGL.

00:36 – First Stall Series
Initial stall test clean configuration — onset, break, and recovery.

01:03 – Stall Results
Observed stall around 48 mph vs 58 mph prior to VG install. 200 ft loss, solid recovery.

01:47 – Flap Configuration Test
Flaps down, slower power-on stall; results slightly better than expected.

02:26 – Dive Test & Trim Change
High-speed dive to 8,500 ft reveals noticeable trim and attitude change.

02:43 – Flight Attitude Shift
Negative tail pressure required; new pitch behavior under same conditions.

03:13 – CFD Validation in Flight
Speed gain of ~2 mph at same density altitude confirms CFD accuracy.

03:53 – Garmin Attitude Indicator Recalibration
Adjusting for changed flight attitude; discussion of horizon alignment.

04:40 – Pattern & Landing Behavior
Revised approach speeds — slower, more stable, but with steeper sight picture.

05:16 – Touchdown Observations
Landing noticeably softer; approach profile recalibrated.

05:53 – Flaps-Down Takeoff Test
Testing VG impact on lift-off characteristics and acceleration.

06:22 – Short Takeoff & Climb Performance
Reduced takeoff roll; similar lift with less power. Substantial improvement.

07:35 – Post-Flight Analysis
Transition to CAD/CFD environment — explaining the test setup and methodology.

08:00 – Wing Model & VG Placement
Airfoil modeled to thousandths of an inch; testing various VG chord locations.

09:00 – Velocity & Pressure Visualization
CFD plots show airflow acceleration, pressure zones, and boundary layer control.

10:16 – Vortex Pattern & Trailing Edge Effect
Visualization of swirl persistence to aileron; optimal placement found.

11:15 – Lift vs Drag Data
Comparing sections with/without VGs — measurable lift gain and drag reduction.

12:01 – Quantitative Results
~1 lb lift increase per section; 0.4 lb drag increase mitigated by improved efficiency.

12:45 – Bubble Analysis & Flow Separation
Identifying low-velocity bubble and how VGs stabilize it near 3.5% chord.

13:35 – Final Placement Rationale
Settled location captures slow air before separation without excessive drag.

#Aviation #FlightTest #ExperimentalAircraft #STOL #BushFlying #CFD #Aerodynamics

Видео Testing Vortex Generators in Flight — Stall Speed Drop & Real-World CFD Results канала Sterling Taylor