![]() used fiber-optic sensors rather than thermocouples to measure temperature. Along with a detailed study of the traditional methods for determining the intensity of heat transfer in various cases, experts also proposed original approaches for solving this thermophysical problem. Determining surface heat flux with depth measurements of temperature via various thermocouples and other special devices is also widespread. improved the design of traditional film sensors in order to enhance the accuracy of measuring shear friction stresses (with subsequent determination of the heat flux) during gas flow in a pipe. The relative uncertainty of the thermal experiment improved by almost 5%. proposed a new thermal sensor with protective heating to improve the accuracy of measuring shear friction stresses in a turbulent flow. For example, the accuracy of determining the heat transfer intensity increased by almost 8%. This made it possible to increase the sensitivity and accuracy of the measurement. developed a new film sensor based on a two-layer substrate structure. Thermocouples under the film record the temperature change over time. These sensors have a conductive film that is heated to a specific temperature to create a temperature difference between the flow and the surface. One of the most common types of sensors are film sensors. A large number of sensors (technical devices) and special techniques for conducting thermophysical experiments have been developed to implement these methods practically. Today, there are reliable methods for measuring heat flow by creating a temperature difference between the medium (gas, liquid) and the surface (channels, pipelines). The main solution consists of determining the heat flux density q c = αΔ T and then calculating the heat transfer coefficient α. An example of a successful application of the proposed method in relation to the study of thermomechanical processes in the gas exchange systems of reciprocating internal combustion engines is described.ĭetermining the intensity of heat transfer at the interface of two media experimentally is a widespread problem in science and technology. The article presents a method for determining the speed of the developed measuring system. This method is based on the Kutateladze–Leontiev approach (the laws of friction and heat transfer) and the hydrodynamic analogy of heat transfer (the Reynolds analogy): this is an assumption about the unity of momentum and heat transfer in a turbulent flow, which establishes a quantitative relationship between friction stresses on the heat exchange surface and heat transfer through this surface. A substrate with the sensor’s sensitive element was mounted flush with the wall of the investigated pipeline. The proposed method uses a constant-temperature hot-wire anemometer and a sensor with a thread sensitive element fixed on the surface of a fluoroplastic substrate. The article provides an overview of modern approaches and technical devices for determining the heat flux or friction stresses on surfaces in the study of thermophysical processes. ![]() An indirect method and procedure for determining the local heat transfer coefficient in experimental studies on the intensity of heat transfer at a gas–surface interface is described.
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