High-Speed Variable-Mach Subsonic Wind Tunnel
Continuously variable subsonic wind tunnel capable of test section speeds from Mach M = 0.15 to 0.75.
Aerospace & Aeronautical Engineering / Prandtl-Glauert Correction
FREE TO EXPLORELABORATORY 16 · AEROSPACE & AERONAUTICAL ENGINEERING
Subsonic Compressibility Corrections and the Prandtl-Glauert Transformation
Quantify the amplification of airfoil pressure coefficients and lift curve slopes as Mach number increases from incompressible (M ~ 0) to high subsonic speeds. Explore interactive wind tunnel simulation, flight dynamics, and aerospace engineering telemetry.
AERODYNAMICS · PROPULSION · FLIGHT DYNAMICS
Your virtual aerospace engineering laboratory.
SUCTION PEAK MAGNITUDE |C_P|—
FLIGHT & TEST CELL TELEMETRY
Ready to sample with 1/beta_PG = 1.1 dimensionless.
Adjust 1/beta_PG, 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
Linearized Prandtl-Glauert theory assumes small perturbations; errors increase for thick airfoils (> 15% thickness) or large alpha. Linear regression of |C_p| against the Prandtl-Glauert factor yields a baseline incompressible suction |C_p0| = 0.6500 with R^2 > 0.999999.
Aeronautical apparatus & wind tunnel sensors.
NACA 0012 High-Speed Wing Model
High-rigidity stainless steel airfoil model (c = 120 mm) with flush-mounted leading-edge static taps.
Fast-Response Kulite Piezoresistive Transducers
Measures leading-edge suction peak pressures with 100 kHz bandwidth to prevent dynamic lag.
Tunnel Upstream Mach Number Controller
Maintains constant test Mach number within +/- 0.002 via variable throat choke valve.
Stagnation Pressure & Temperature Monitor
Monitors total conditions (P_0, T_0) to compute dynamic pressure and Reynolds number.
Digital Data Acquisition Workstation
Computes normalized pressure coefficients C_p and performs Prandtl-Glauert linear regression.
FOLLOW THE METHOD
A reason behind every step.
Quantify the amplification of airfoil pressure coefficients and lift curve slopes as Mach number increases from incompressible (M ~ 0) to high subsonic speeds. Standardized parameter settings: 1.02, 1.064, 1.12, 1.195, 1.291, 1.414 dimensionless.
01
Model Pitch Trimming
Set the NACA 0012 model angle of attack to a constant alpha = 4.0 degrees, locking the turntable mechanism rigidly.
02
Low-Speed Incompressible Baseline
Establish baseline flow at Mach M_inf = 0.20 (1/sqrt(1-M^2) = 1.020) and record the baseline incompressible suction peak C_p0.
03
Mach Number Stepping
Step wind tunnel speed through Mach M_inf = 0.34, 0.45, 0.55, 0.63, and 0.71 (corresponding to 1/beta_PG = 1.064 to 1.414).
04
Suction Peak Pressure Sampling
Acquire 5000 static pressure samples at the leading-edge suction peak tap (x/c = 0.05) at each Mach plateau.
05
Pressure Coefficient Normalization
Compute C_p = (P_static - P_inf) / q_inf at each Mach number, taking absolute value |C_p|.
06
Prandtl-Glauert Linear Regression
Plot |C_p| versus 1/sqrt(1 - M_inf^2), perform linear regression to determine the slope, and verify the Prandtl-Glauert rule up to M_crit.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into aerodynamic insight.
Points are your recorded observations. The solid regression line validates Prandtl-Glauert Correction mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
|C_p(M)| = \frac{|C_{p0}|}{\sqrt{1 - M_\infty^2}} \implies |C_p| = m \cdot \left(\frac{1}{\sqrt{1 - M_\infty^2}}\right) + b
| # | Prandtl-Glauert Amplification Factor (dimensionless) | Suction Peak Magnitude |C_p| (dimensionless) | Prandtl-Glauert Factor 1 / sqrt(1 - M_inf^2) | Suction Peak Pressure Coefficient |C_p| | Remove |
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