A solid-state concentration sensor for wind tunnel dispersion measurement
Lead Research Organisation:
University of Surrey
Department Name: Mechanical Engineering Sciences
Abstract
Studying how air pollution moves around between buildings is a very complicated problem: the flow of wind between buildings can be chaotic and unpredictable; the weather conditions are always changing, and there are many different possible sources of pollution. Wind tunnel measurements are still a valuable, trusted and efficient way to study how pollution spreads under these conditions.
To simulate pollution, a tracer gas that can be detected by specialised sensors is used. These sensors are accurate and fast, but very, very expensive. On the other hand, you can get inexpensive microchip-based sensors now that can detect specific gases very accurately. The purpose of our project is to adapt these inexpensive sensors to the specialised application of measuring tracer gases in wind tunnels. The challenges here are getting the slow microchip sensors to work much more quickly, and to build a probe around the sensor that can quickly suck up small amounts of gas and get that gas to the sensors.
If successful, we would be able to use large numbers of tracer gas probes at the same time: this means that (a) we could compare what was happening over large areas in the wind tunnel, despite how chaotic the flow can be- and (b) we could measure many points at once, drastically reducing the amount of time that the wind tunnel would need to run. We may even be able to get probes to respond to more than one type of tracer gas at the same time: this is something that hasn't been done before, so it would open up new avenues of research.
To simulate pollution, a tracer gas that can be detected by specialised sensors is used. These sensors are accurate and fast, but very, very expensive. On the other hand, you can get inexpensive microchip-based sensors now that can detect specific gases very accurately. The purpose of our project is to adapt these inexpensive sensors to the specialised application of measuring tracer gases in wind tunnels. The challenges here are getting the slow microchip sensors to work much more quickly, and to build a probe around the sensor that can quickly suck up small amounts of gas and get that gas to the sensors.
If successful, we would be able to use large numbers of tracer gas probes at the same time: this means that (a) we could compare what was happening over large areas in the wind tunnel, despite how chaotic the flow can be- and (b) we could measure many points at once, drastically reducing the amount of time that the wind tunnel would need to run. We may even be able to get probes to respond to more than one type of tracer gas at the same time: this is something that hasn't been done before, so it would open up new avenues of research.
Organisations
| Description | The 'Smart Cube' facility was completed and is now available for use by the community. In addition, a number of new measurement techniques were developed in order to take full advantage of the capability of the facility. |
| Exploitation Route | The facility itself is available to the community, and there are funding bids in preparation/submission now which will use this facility as a critical piece of experimental infrastructure. Additional technologies, including calibration techniques and apparatus, were also developed and may be publishable in the near future. |
| Sectors | Aerospace Defence and Marine Environment Other |
| Description | (1) The cube facility itself was used in the validation of a new, high-precision wind tunnel wall correction methodology being developed in collaboration with commercial parnters. (2) The process of integrating the cube systems has highlighted some of the complications in managing very high data volumes; this was fed back to the sensor manufacturer and their subcontractors, who have now changed the network communication process for their products. (3) The dynamic calibration technique developed for use with the facility has been adapted for use with solid-state gas sensors for another project, and this technology is being developed by a commercial partner. |
| First Year Of Impact | 2023 |
| Sector | Environment,Healthcare |
| Title | Time-resolved hydrocarbon probe |
| Description | This project demonstrated that it was possible to dynamically calibrate a low-bandwidth pellistor sensor normally used for safety applications, increasing the response time of the sensor by an order of magnitude. The technology is being developed into a low-cost, field-deployable probe. |
| Type Of Technology | New/Improved Technique/Technology |
| Year Produced | 2023 |
| Impact | The technology led to collaborations to develop the technical product for use in field gas flux applications, including agriculture and wastewater management. |