gSKIN® Heat Flux Sensors find application in many areas. On this webpage you will find FAQs concerning questions in most popular application areas of our products, case studies prepared by greenTEG in order to explain how to use our sensors, and scientific publications, where gSKIN® Heat Flux Sensors have been used by our customers. In case of any additional questions please contact us.

Scientific Publications of research with greenTEG’s sensors

Local heat transfer characteristics of a slot nozzle array for batch drying of thin films under industrial process conditions

For optimizing the drying process of thin functional films, knowledge of the relevant influencing parameters is needed. One paramount parameter for design of experimental conditions and the accurate interpretation of experimental data is the heat transfer coefficient inside a dryer. Information on the heat transfer in a dryer also facilitates a reliable transfer of results obtained in laboratory set-ups to industrial production. In this work, the heat transfer in a batch drying set-up with an array of slot nozzles is investigated. The measurement arrangement consists of a heat flux sensor mounted on the surface of a temperature-controlled plate. For validation of this arrangement, heat transfer measurements with a single round nozzle were compared to transient heat transfer experiments using thermochromic liquid crystals. The data measured in the batch drying set-up show a periodically homogenous distribution of heat transfer coefficients for the investigated 16 nozzles. This gives the possibility to dry thin films with a coating length of up to 800 mm in the set-up at constant conditions along the coating length. A prerequisite is a periodical movement with an amplitude of at least one nozzle-to-nozzle spacing.

Journal of Coatings Technology and Research 12 (5) 915-920, 2015

More information: springer.com

Solid-state thermal diode with shape memory alloys

Analogous to the electronic diode, a thermal diode transports heat mainly in one preferential direction rather than in the opposite direction. Phase change thermal diodes usually rectify heat transport much more effectively than solid state thermal diodes due to the latent heat phase change effect. However, they are limited by either the gravitational orientation or one dimensional configuration. On the other hand, solid state thermal diodes come in many shapes and sizes, durable, relatively easy to construct, and are simple to operate, but their diodicity (rectification coefficient) is always in the order of g 1 or lower. Thus, it is difficult to find any potential applications. In order to be practically useful for most engineering systems, a thermal diode should exhibit a diodicity in the order of g 10 or greater. In this study, a passive solid state thermal diode with shape memory alloy is built and investigated experimentally. The diodicity is recorded at about 90. This promising result could have important applications in the development of future thermal circuits or for thermal management.

The International Journal of Heat and Mass Transfer 93 (2016) 

More information: sciencedirect.com

Hollow Silica as an Optically Transparent and Thermally Insulating Polymer Additive

We present an improved synthesis route to hollow silica particles starting from tetramethyl orthosilicate (TMOS) instead of the traditionally used ethyl ester. The silica was first deposited onto polystyrene (PS) particles that were later removed. The here introduced, apparently minor modification in synthesis, however, allowed for a very high purity material. The improved, low density hollow silica particles were successfully implemented into polymer films and permitted maintaining optical transparency while significantly improving the heat barrier properties of the composite. Mechanistic investigations revealed the dominant role of here used methanol as a cosolvent and its role in controlling the hydrolysis rate of the silicic ester, and subsequent formation of hollow silica particles. Systematic experiments using various reaction parameters revealed a transition between regions of inhomogeneous material production at fast hydrolysis rate and reliable silica deposition on the surface of PS as a core–shell structured particle. The shell-thickness was controlled from 6.2 to 17.4 nm by increasing TMOS concentration and the diameter from 95 to 430 nm through use of the different sizes of PS particles. Hollow silica particle with the shell-thickness about 6.2 nm displayed a high light transmittance intensity up to 95% at 680 nm (length of light path ∼ 1 cm). Polyethersulfone (PES)/hollow silica composite films (35 ± 5 μm thick) exhibited a much lower thermal conductivity (0.03 ± 0.005 W m·K–1) than pure polymer films. This indicates that the prepared hollow silica is able to be used for cost and energy effective optical devices requiring thermal insulation.

Langmuir 2016, 32 (1)

More information: acs.org

List of Case Studies and Application Notes by greenTEG

Convective Heat Flux Explained

Thermal convection is one of the three mechanisms of heat transfer, besides conduction and thermal radiation. The heat is transferred by a moving fluid (e.g. wind or water), and is usually the dominant form of heat transfer in liquids and gases. Convection can be divided into natural convection and forced convection. Download the full explanation.

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gSKIN® Case Study: Battery Calorimetry Using greenTEG’s Heat Flux Sensors

In this case study we demonstrate how heat flux sensors can help determining the state of health of a battery. Download the case study.

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Monitoring Heat Generation of Batteries

Read in this case study how the heat generated by a battery can be monitored with a gSKIN Heat Flux Sensor. Download the case study.

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Review our FAQs concerning questions and answers in the most popular application areas. In case of additional enquiries please contact us.

Heat Flux Measurement

Calorimetric Measurements of Batteries

Phase Change Materials Investigations

Textile Thermal Properties Measurements