Elucidation of Heat / Mass Transfer Phenomena

Evaluation of Interface Thermal Resistance

Thermal vibration in materials

In general polymer materials, heat conduction due to phonon vibration is considered to be the main factor of heat transfer phenomena. For this reason, interface thermal resistance is expected to occur if molecules do not interpenetrate at the bonding interface of dissimilar materials. Our laboratory has reported that there is a correlation between interface thermal resistance and material affinity, and that interface thermal resistance increases with lower material affinity. At present, we are conducting research on the effect on interface thermal resistance given by the change in material affinity due to the addition of a compatibilizer, and on the analogy of interfacial bonding strength and interfacial thermal resistance.

Creation of Excellent Boiling Heat Transfer Surface using Cu Nano-particles Sintered Layer

SEM image of thermally treated metal nanoparticles

Boiling heat transfer attracts attention as a method for efficiently cooling electronic devices with high heat generation density by improving the performance of electronic devices. In this research, we aim to create a heat transfer surface with excellent heat transfer characteristics using a porous body obtained by heat treatment of copper nanoparticles. The improvement of the critical heat flux can be obtained by the control of the wettability by the fine irregularities on the surface of the heat transfer surface, and the supply of the efficient working fluid to the heat transfer surface by the capillary force inside the porous layer.

Development of Thermal Flow Measurement Technology and Its Advancement

Internal flow elucidation of automobile oxygen sensor

Appearance of a small experimental wind tunnel

An oxygen sensor attached to the exhaust pipe of a car needs to detect harmful substances in exhaust gas with high accuracy and time response. However, because a dual cylindrical protector is provided to protect the oxygen sensor element installed in harsh environments, there is a problem that the reliability of oxygen concentration measurement decreases. Therefore, in this research, we investigate how exhaust gas reaches the sensor element surface. Specifically, flow fields around and inside an acrylic oxygen sensor model installed inside a device (experimental wind tunnel) that simulates the internal environment of the exhaust pipe of a car is measured by using a visible light laser and a high-speed camera.

Development of New Type of Gas Flowmeter using Ultrasound

Ultrasonic transducer array

With the aim of accurately and quickly measuring the flow rate of gases represented by air, we are developing new types of gas flowmeters with an approach different from conventional transit time method and Doppler method.

Highly Functional Thermal Processing Technology Development

Advancement of Kneading Technology of Viscoelastic Fluid Represented by Rubber

Speed distribution during kneading

In the production of rubber, the process of mixing various ingredients with raw material rubber greatly affects the quality and life of the final product. For this reason, it is very important to elucidate the behavior of the rubber that is kneaded with a mixer etc. Through the investigation in this research, it was found that the shear-thinning property of the rubber and the filling rate of the fluid affect the kneading behavior and influence the chemical reaction caused by the compounding agent in the rubber. At present, we are conducting research on the dispersion behavior of compounding agents when mixed with a mixer.