Multi-Tube Total Pressure Wake Rake
Array of 48 hyper-fine total pressure tubes spaced 2 mm apart across the wake cross-section.
Aerospace & Aeronautical Engineering / Wake Survey Profile Drag
FREE TO EXPLORELABORATORY 06 · AEROSPACE & AERONAUTICAL ENGINEERING
Wake Survey and Profile Drag Determination by Momentum Deficit
Determine section profile drag coefficient c_d of an airfoil using a downstream total-head wake survey rake and the Jones-Betz momentum deficit integral. Explore interactive wind tunnel simulation, flight dynamics, and aerospace engineering telemetry.
AERODYNAMICS · PROPULSION · FLIGHT DYNAMICS
Your virtual aerospace engineering laboratory.
PROFILE DRAG COEFFICIENT C_D—
FLIGHT & TEST CELL TELEMETRY
Ready to sample with Deficit = 0.3 dimensionless.
Adjust Deficit, then execute aerospace trial.
Aeronautical telemetry and flight states are evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity aerodynamic modeling.
Aeronautical assumptions and boundary condition limits
The Jones formula assumes static pressure across the wake survey plane has recovered to ambient free-stream static pressure. The ordinary least-squares fit across wake deficit samples yields an empirical section drag coefficient c_d = 0.0240 matching the integrated momentum deficit with R^2 > 0.999999.
Aeronautical apparatus & wind tunnel sensors.
NACA 0012 Airfoil Model (c = 150 mm)
Spanwise uniform model mounted between optical glass wind tunnel sidewalls to maintain two-dimensional flow.
Multi-Channel Scanivalve Pressure Transducer
Acquires simultaneous differential pressures from all 48 rake tubes relative to free-stream static.
Pitot-Static Reference Mast
Measures undisturbed upstream total pressure P_0_inf and dynamic pressure q_inf.
Automated Transverse Wake Traverse
Positions wake rake across the vertical wake slice from -50 mm to +50 mm relative to chord line.
Digital Integration DAQ System
Executes real-time Jones-Betz momentum integral quadrature across wake velocity points.
FOLLOW THE METHOD
A reason behind every step.
Determine section profile drag coefficient c_d of an airfoil using a downstream total-head wake survey rake and the Jones-Betz momentum deficit integral. Standardized parameter settings: 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 dimensionless.
01
Wake Rake Positioning
Mount the wake rake exactly 1.0 chord length downstream of the model trailing edge, centered on the model wake axis.
02
Wind Tunnel Stabilization
Bring wind tunnel airspeed to V_inf = 35 m/s, stabilizing free-stream dynamic pressure at q_inf = 750 Pa.
03
Baseline Zero-Incidence Survey
Set airfoil angle of attack to alpha = 0 deg and record baseline wake total pressure deficit across all 48 channels.
04
Systematic Wake Deficit Stepping
Adjust model incidence to achieve peak wake deficit ratios Delta q / q_inf of 0.10, 0.20, 0.30, 0.40, 0.50, and 0.60.
05
Velocity Deficit Conversion
Compute local wake dynamic pressure ratio q_w / q_inf and local velocity ratio u_w / U_inf for every wake probe.
06
Jones Integral Quadrature
Integrate the Jones momentum deficit integrand across the wake width to calculate the section profile drag coefficient c_d.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into aerodynamic insight.
Points are your recorded observations. The solid regression line validates Wake Survey Profile Drag mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
c_d = 2 \int \sqrt{\frac{q_w}{q_\infty}} \left(1 - \sqrt{\frac{q_w}{q_\infty}}\right) d\left(\frac{y}{c}\right) \implies c_d = m \cdot (\text{Deficit Ratio}) + b
| # | Peak Wake Deficit Ratio (dimensionless) | Profile Drag Coefficient c_d (dimensionless) | Peak Dynamic Head Deficit Ratio Delta q / q_inf | Section Profile Drag Coefficient c_d | Remove |
|---|
No readings yet. Execute an aerodynamic trial and record it.
Calculate it yourself.
CHECK YOUR UNDERSTANDING