Novel microthermal sensor principle for determining the mixture ratio of binary fluid mixtures using Föppl vortices
A novel sensor principle for determining binary fluid mixtures of known components is presented, making use of different thermal and rheological properties of the mixture's components. Using a microheater, a heat pulse is introduced in the mixture. The resulting temperature increase depends on...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-06-01
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| Series: | Journal of Sensors and Sensor Systems |
| Online Access: | http://www.j-sens-sens-syst.net/4/239/2015/jsss-4-239-2015.pdf |
| Summary: | A novel sensor principle for determining binary fluid mixtures of known
components is presented, making use of different thermal and rheological
properties of the mixture's components. Using a microheater, a heat pulse is
introduced in the mixture. The resulting temperature increase depends on the
thermal properties of the mixture, allowing determination of the mixture
ratio. Placing a bluff body in the fluid channel causes the formation of a
stationary pair of vortices behind the body. The length of the vortex pair
depends on the mixture's viscosity and thus its composition. By placing
the microheater in the vortex area and making use of forced convection which
changes with the size of the vortex, the sensitivity for determination of the
mixture ratio can be increased by a factor of 2.5 compared to the direct
thermal measurement. The flow velocity is measured independently of the
mixture ratio using time-of-flight thermal anemometry. |
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| ISSN: | 2194-8771 2194-878X |