A Numerical Analysis of Wall Heat Transfer of Diesel Spray Flame using Large Eddy Simulation with High Spatial Resolution

Tatsuya Kuboyama･Tetsu Kadohata (Chiba University)･Shin Kimura (Sustainable Engine Research Center)･Yasuo Moriyoshi (Chiba University)

This study aims to investigate the detailed mechanism of the wall heat transfer of the diesel spray flame to improve the prediction accuracy of the wall heat transfer model in engine combustion simulations. An LES analysis with fine grids aligned on the wall with enough resolution to solve the viscous sublayer without using a heat transfer model near the wall.

An Experimental Method for the Development of Vehicle Thermal Management Systems using Transient Thermal Control Devices

Hirotaka Iseki･Ryo Yoshimura･Seiji Hirai･Toshiyuki Michikita (HORIBA)

The proliferation of electrified vehicles incorporating increasingly complex thermal management systems demands more efficient approaches to developing these systems. A transient thermal control device that emulates heat sources, such as batteries and powertrains, has been used to replicate the heat exchange between the heat sources and coolant circuit based on the JAMBE thermal model. To demonstrate the applicability of the transient thermal control device for evaluating thermal management systems without physical heat sources, the reproduction accuracy of the thermal control device with respect to a model is validated; this demonstrates its potential for evaluating complex systems without full thermal systems.

Comparison of Nucleate Flow Boiling Heat Transfer on Aluminum Heating Surface Using Distilled Water, Ethylene Glycol Aqueous Solution, and Long-Life Coolant for IC Engine Cooling System

Emir Yilmaz･Takashi Suzuki･Kota Suzuki･Shota Ishii･Minato Suzuki･Kodai Kato･Mayu Watanabe･Mitsuhisa Ichiyanagi (Sophia University)

Understanding the relation between coolant composition and surface properties is crucial for improving nucleate boiling heat transfer in IC engine cooling. This study examined heat transfer mechanisms, including latent and sensible heat transport, and bubble dynamics, using distilled water, ethylene glycol aqueous solution (EG50%), and LLC under flow boiling conditions. Results revealed that due to corrosion bubble nucleation was reduced for distilled water and EG50% coolants, while LLC preserved surface wettability and bubble behavior. Increased coolant viscosity and surface wettability influenced latent and sensible heat transport, offering insights into optimizing coolant formulations and mitigating corrosion effects for improved cooling performance.

Development of a Compact Rankine Cycle Generator with an Integrated-Component Structure
-Eighth Report: Metallization of Parts and Experiment with Refrigerant-

Katsuyuki Tanaka･Chigusa Nakagawa･Tetsuhiro Wakiyama･Nana Tonooka･Kenya Ohtsuka (Nihon Univ.)

We are developing a compact Rankine cycle generator with an integrated-component structure to convert waste heat from automobiles into electricity. We will report the parts made of metal and experiment results using a refrigerant.

Energy Recovery Experiment Using a 5kW-class Rankine Cycle Generator with Engine Waste Heat from Heavy Duty Vehicles
-First report: Construction of Experimental Equipment and Performance Test-

Ryotaro Kobitsu･Hiroki Kato･Waka Katoono･Masanari Saito･Kenya Ohtsuka･Katsuyuki Tanaka (Nihon Univ.)･Masaki Naruke･Takaaki Kitamura (JARI)

We are conducting an energy recovery experiment using a 5kW class Rankine cycle generator to convert the engine waste heat of heavy duty vehicles into electricity. We attached a commercially available 5kW-class Rankine cycle generator to the engine of a heavy duty vehicle, connected it with piping to transfer waste heat, and conducted a trial experiment. We will report on the results.

Thermoelectric Materials for Hybrid Electrical Vehicle with Lean Burn Engine

Michihiro Ohta･Philipp Sauerschnig･Kishor Kumar Johari (AIST)･Masaki Naruke (JARI)･Kazuki Imasato･Masanobu Miyata･Takao Ishida･Atsushi Yamamoto (AIST)

We have developed the Mg3(Sb,Bi)2 and Bi2Te3-based thermoelectric materials for waste heat recovery in HEV with lean burn engine. In Mg3(Sb,Bi)2, the thermoelectric figure of merit in the exhaust temperature range was successfully enhanced by tuning the Sb/Bi ratio. The mechanical properties of the thermoelectric materials were investigated through compression testing. The improvement of fuel economy in the vehicle by the developed thermoelectric materials was simulated by GT-SUITE software.

Thermoelectric power generation performance by heat recovery from exhaust gas

hiroyasu mino･satoshi someya･toshie koyama (Tokyo Denki University)

We evaluated the power generation performance of a commercially available thermoelectric module for heat recovery from exhaust gas, and found that the module could generate 2.35 W/piece at ΔT110°C. We also evaluated liquid-liquid systems, such as hot and cold water, and solid-state heat transfer, and compared the performance. The basic performance of the thermoelectric modules and the heat recovery performance from exhaust gas were summarized.