NUMERICAL ANALYSIS AND SCALED-DOWN MODEL OF AIR BARRIER AND BLOCKING ANGLE VARIATIONS IN SUPPLY DUCT DIFFUSER IN HIGH-SPEED TRAIN CABINS TO COMPLY WITH INDONESIAN THERMAL COMFORT
Abstract
Kereta Cepat Merah Putih (KCMP) was a high-speed train developed by the Indonesian government to enhance intercity travel. A key focus of this development was the HVAC system within the passenger cabin, essential for ensuring passenger comfort. This study investigated the impact of air barrier placement and air flow direction angles (45°, 90°, and 135°) on airspeed and temperature distribution in the cabin. Using CFD simulations with ANSYS Fluent, six variations were tested to determine the optimal configuration. The results identified variation model 3, which employed an air barrier at the top of the ducting system and omitted the use of blocking angles for the air flow direction of the supply diffuser, as the most effective in achieving optimal airspeed and temperature distribution. Following the simulation, experimental measurements were conducted on a scaled-down model of variation 3. Measurements were taken at six sample planes in the supply duct and five in the supply duct diffuser, applying the duct traversing method (ISO 3966) with 25 measurement points per sample plane. The experimental results were then compared with the simulation data to ensure consistency in volumetric flow rate, flow velocity, and air pressure drop parameters. Additionally, comparisons were made with similar trains, measuring air velocity and temperature distribution within their passenger cabins. The findings confirmed that the performance of variation model 3 in the CFD simulation aligned with the scaled-down experimental results, demonstrating consistency in both tests and comparisons.
References
SARNA, I., PALMOWSKA, A. (2019). MODELLING OF THE AIR FLOW IN THE PASSENGER COACH. Architecture Civil Engineering Environment Journal, vol. 12, no. 4, 125-133, DOI: 10.21307/ACEE-2019-058.
Haller, G. (2006). Thermal Comfort in Rail Vehicles. RTA Rail Tec Arsenal Fahrzeugversuchsanlage GmbH, Vienna.
Rugh, P., Bharathan, D. (2005). Predicting Human Thermal Comfort in Automobiles. SAE Technical Papers 2005-01-2008, 11, DOI: 10.4271/2005-01-2008.
Min, A., Fan, Y., Wei, H., Zhang, L., Jing, L., Han, Y., Yu, F. (2017). Numerical Study on Aerodynamic Characteristics of High-Speed Trains with Considering Thermal-Flow Coupling Effects. Journal of Vibroengineering, vol. 19, no. 7, 5606-5626, DOI: 10.21595/jve.2017.18778.
Yang, Lin. Li, Mengxi. Li, Xiangdong. and Tu, Jiyuan. (2024). The Effects of Diffuser Type on Thermal Flow and Contaminant Transport in High-Speed Train (HST) Cabins – A Numerical Study. International Journal of Ventilation, vol. 17, no. 1, 48-62, DOI: 10.1080/14733315.2017.1351736
Suárez, C., Iranzo, A., Salva, J. A., Tapia, E., Barea, G., & Guerra, J. (2017). Parametric Investigation Using Computational Fluid Dynamics of the HVAC Air Distribution in a Railway Vehicle for Representative Weather and Operating Conditions. Energies, vol. 10, no.8, 1074. DOI: 10.3390/en10081074
Menteri Perhubungan RI (2019). Peraturan Menteri Perhubungan Republik Indonesia Nomor PM 69 Tahun 2019 Tentang Standar Spesifikasi Teknis Kereta Api Kecepatan Tinggi. Kementerian Perhubungan Republik Indonesia, Jakarta.
Selamat, H., Fadzli, M., Mat, Z., Mohammad, S., Mohd, F., Al’Hapis, M. (2020). Review on HVAC System Optimization Towards Energy Saving Building Operation. International Energy Journal. vol. 20, no. 3. 345-358.
Fauzun, F., Yogiswara, C. W., Ariyadi, H. M., Taufiqurrahman, M. S., Ritonga, A. F., Pranoto, I., Garingging, R. A., Areli, F., Putra, R. K., Al-Qadri, M. H., Fatkhi, A. S., Nurdiansyah, R. T., & Restu, F. R. (2023). Numerical Study the Effect of Air Barriers Height Inside the Air Conditioning Ducting to Satisfy the Regulation of Indonesia Minister of Transportation Number 69 Of 2019. Journal of Applied Engineering Science, vol. 21, no. 4, 1156–1170, DOI: 10.5937/jaes0-45415.
Incropera, F. P., DeWitt, D. P., Bergman, T. L., Lavine, A. S. (2006). Fundamentals of Heat and Mass Transfer Sixth Edition. McGraw-Hill, New York.
Seeni, A., Rajendran, P., Mamat, H. (2019). A CFD Mesh Independent Solution Technique for Low Reynolds Number Propeller. CFD Letters Journal, vol. 11, no. 10, 15-30.
Cengel, Y., Cimbala, J. (2015). Fluid Mechanics: Fundamental and Applications. McGraw-Hill, New York.
Caré, I., Bonthoux, F., Fontaine, J. (2014). Measurement of Air Flow in Duct by Velocity Measurements. EPJ Web of Conferences, vol. 77. 16th International Congress of Metrology, DOI: 10.1051/epjconf/20147700010.
Li, C., Herrin, D. (2022). Scaled Down Measurement of HVAC Duct Insertion Loss and Comparison to Simulation. INTER-NOISE and NOISE-CON Congress and Conference Proceedings, vol. 264, no. 1, 909–916. DOI: 10.3397/nc-2022-834.
