Related Experiment Video
Updated: Apr 13, 2026

High-speed Particle Image Velocimetry Near Surfaces
Published on: June 24, 2013
Seedless velocimetry of high-enthalpy hypersonic boundary layers by nitric oxide ionization induced flow tagging and
Abstract:
This Letter describes the first, to the best of our knowledge, demonstration of a velocity measurement by nitric oxide ionization induced flow tagging and imaging (NiiFTI) of a high-enthalpy hypersonic flow utilizing naturally formed nitric oxide. The measurements were conducted in the hypervelocity expansion tunnel (HXT) at Texas A&M University in Mach 8.5 and Mach 10 flows near an ogive test article. The region of interest contained boundary layers (BL) and the hot flow region behind the oblique shock front. The BL profiles were recorded with the velocity ranging between 2516 m/s and 985 m/s measured as close as 0.5 mm to the model surface. Single-shot measurement in the core flow showed an average velocity of 2.5 km/s with a slight decelerating trend. Overall, NiiFTI demonstrated a good performance in high-enthalpy hypersonic flow, extending its usability to reacting environments.
Related Concept Videos
Laminar and Turbulent Flow
Velocity and Acceleration in Steady and Unsteady Flow
The acceleration can be generalized to any point in the flow, and expressed as components along three perpendicular directions, representing changes in velocity over...
Steady, Laminar Flow Between Parallel Plates
Couette Flow
Steady, Laminar Flow in Circular Tubes
Rapidly Varying Flow

