Manchester Researchers Build Temperature-Resilient Luminescent Paint for Supersonic Aerodynamic Testing

Researchers at The University of Manchester have developed a pressure-sensitive coating designed to measure aerodynamic pressure on aircraft and spacecraft scale models without the thermal distortion that traditionally impairs optical wind tunnel measurements. According to reporting by TechXplore (https://techxplore.com/news/2026-09-air-pressure-future-aircraft.html), the new material cuts temperature sensitivity by 25 percent relative to the existing industry benchmark, maintaining measurement integrity under high-velocity airflow.

Aerospace engineers routinely evaluate scale models in wind tunnels to gauge how air pressure distributes across complex surfaces, a critical metric for fuel efficiency, vehicle control, and structural integrity. Standard pressure-sensitive paints glow in proportion to local air pressure, but they are also sensitive to heat. Because scale models undergo rapid heating and cooling cycles during high-speed testing, thermal variance shifts the paint's optical output, requiring engineers to correct for temperature interference in post-test data analysis.

To isolate pressure readings, an interdisciplinary team from Manchester's Department of Chemistry and Department of Mechanical and Aerospace Engineering locked a light-emitting, platinum-based compound into a plastic matrix similar to Teflon. In standard paint formulations, luminescent molecules can aggregate, which increases their sensitivity to thermal fluctuations. Anchoring the active molecules—part of the porphyrin family—directly into the polymer framework chemically prevents this clustering.

Laboratory testing demonstrated that the immobilized compound reduced the coating's temperature sensitivity to 0.3 percent per degree Celsius. The team detailed their findings in the journal ACS Applied Engineering Materials in a paper titled 'Low-Temperature Dependency Pressure-Sensitive Paints for Wind Tunnel Testing Based on Luminescent Polymer-Bound Porphyrins.'

'When you're testing a vehicle at high speed it can heat and cool dramatically based on its aerodynamic design,' said Dr. Elliott Nunn, a researcher in the Department of Chemistry at The University of Manchester and first author of the study. 'By creating a pressure-sensitive paint which doesn't respond as strongly to this heat, we've got something that's much closer to measuring exactly what we want to measure. Our hope is that this will really help the engineers designing the next generation of high-performance and more sustainable aircraft and spacecraft, to make better-informed decisions through cleaner data.'

To test the formulation under operational stress, the researchers coated a cone-shaped model designed to generate complex airflow patterns and placed it in a supersonic wind tunnel where air speeds exceed Mach 5. Despite wide temperature variations across the surface of the test body, the coating recorded pressure distributions that aligned closely with computational simulations.

The optical fidelity of the coating also allowed the team to track Görtler vortices—corkscrew-shaped flow structures that form along concave surfaces. Capturing these vortices is essential for modeling how thin boundary air layers behave at extreme velocities.

'Getting this chemistry right was thanks to a creative collaboration between our chemistry group and the aerospace engineering team—basically, they knew what the paint needed to do in a wind tunnel, and we knew how to create something that could do it,' said Dr. Louise Natrajan, a reader in the Inorganic Chemistry Group at The University of Manchester. The research team plans to conduct further tests across a broader range of aerodynamic conditions to confirm the coating's reliability for commercial and defense aerospace programs.