Srinakharinwirot University Engineering Journal

Assessment of Mun River Overbank and Diversion Strategies for Flood Mitigation in Ubon Ratchathani Province

Supaporn Thongtem, Chaiyapong Thepprasit — Thu, 31 Jul 2025 00:00:00 +0700

This study aimed to investigate flood conditions using the HEC-RAS 2D model, based on the 2019 flood event, which represented a 20-year return period. The simulation focused on overbank flooding from the Mun River in Ubon Ratchathani Province and evaluated the effectiveness of proposed flood diversion canal schemes. The Manning’s roughness coefficients used were 0.040–0.045 within the river channel and 0.07–0.12 for the floodplain. The model was calibrated and validated using data from the 2022 and 2019 flood events. Model performance was assessed using the coefficient of determination (R²) and root mean square error (RMSE), yielding R² = 0.978 and RMSE = 0.057 for calibration, and R² = 0.964 and RMSE = 0.14 for validation, indicating high model reliability. The simulation revealed a flood extent of 362.21 km², with a peak water surface elevation of 115.86 m MSL and a flood duration of 29 days. Three flood diversion scenarios were analyzed: (1) a canal diverting flow from the Chi River to downstream of Pak Mun Dam, (2) a canal diverting flow from the Mun River and Huai Khayung to downstream of Kaeng Saphue (bypassing Ubon Ratchathani urban area), and (3) a combined implementation of both canals. The results showed reductions in flood extent to 321.30, 328.12, and 270.60 km²; peak flood levels to 114.78, 114.65, and 113.44 m MSL; and flood durations to 26, 22, and 16 days, respectively. Scenario 3 was the most effective, reducing the overbank depth of the Mun River to 1.42 meters. This significantly mitigated flooding severity in low-lying areas, protected urban economic zones, and preserved main transportation routes.

Drying Behavior of Khao Dawk Mali 105 Jasmine Paddy in a Spouted Bed Dryer Assisted by Microwave

Thamarat Yabsungnoen, Krawee Treeamnuk, Tawarat Treeamnuk, Jirawat Garluna — Fri, 01 Aug 2025 00:00:00 +0700

This study aimed to compare the drying behavior of paddy rice using two main drying approaches: hot air drying alone and microwave-assisted drying combined with ambient air. The experiments were conducted under four drying conditions: (1) hot air drying at 80°C, (2) hot air drying at 80°C combined with microwave energy at 160 W, (3) microwave drying at 160 W combined with ambient air, and (4) microwave drying at 320 W combined with ambient air. The results showed that drying with hot air combined with microwave energy at 160 W yielded the lowest equilibrium moisture content, at 4.5% wet basis, and the highest drying rate, at approximately 1.25 g_H20/min. In contrast, drying with microwave energy at 160 W combined with ambient air resulted in the highest equilibrium moisture content, at 12.5% wet basis, and the lowest drying rate, approximately 0.525 g_H20/min. Furthermore, it was found that the specific energy consumption (SEC) of the hot air–microwave method tended to increase significantly in the low-moisture content region. This method also resulted in the lowest head rice yield, at 2%. On the other hand, microwave drying at 160 W alone yielded the highest head rice percentage, at 38%, and the lowest SEC. These differences indicate that excessive energy input may generate internal stresses within the kernels, leading to greater damage. Overall, the combination of hot air and microwave drying effectively reduces drying time; however, energy input must be carefully controlled to preserve the quality of the rice, particularly the head rice yield and whiteness, which may deteriorate under overly intense drying conditions.

Solar Electric Vehicle Body Design Inspired by the Peregrine Falcon for Aerodynamic Drag Reduction

jirawat garluna, Thamarat Yabsungnoen — Wed, 30 Jul 2025 00:00:00 +0700

This research presents the design of a solar-powered electric vehicle body using a biomimetic approach inspired by the shape of the Peregrine Falcon, a bird known for its streamlined form and high-speed flight. Three vehicle models were developed and analyzed using Computational Fluid Dynamics (CFD) at wind speeds of 80 and 120 kilometers per hour. The study found that Model 3, which was refined to be more streamlined and practically applicable, achieved a reduction in the aerodynamic drag coefficient from 0.164 to 0.139. However, the lift coefficient increased from 0.0276 to 0.095. The improved model effectively reduced airflow separation and vortex formation at the rear of the vehicle, resulting in better aerodynamic flow performance. Furthermore, the use of CFD simulations significantly reduced both the time and cost required for prototype development. The findings demonstrate that this nature-inspired design approach has strong potential for the development of low-drag solar electric vehicles and can be effectively applied to future clean energy vehicle design.

Performance Evaluation of U-Turn Bridge Deck Rehabilitation: A Case Study on Highway No. 35 Thailand

Kittamet Meepunyo, Wanchai Yodsudjai, Sukit Yindeesuk — Mon, 06 Oct 2025 00:00:00 +0700

This research aims to evaluate the structural performance of a U-turn bridge by analyzing its deflection behavior and internal forces both before and during the rehabilitation process, in order to assess structural stability and safety throughout the construction phase. The study focuses on comparing two rehabilitation approaches: one without steel girder reinforcement and the other with steel girder reinforcement, to examine the impacts of each method. The results indicate that rehabilitation without girder reinforcement led to an average deflection increase of 188.2% compared to the pre-rehabilitation condition. In contrast, the use of steel girders reduced the average deflection by 67.3% compared to the non-reinforced method. These findings clearly demonstrate that steel girder reinforcement significantly enhances the safety and stability of the structure during rehabilitation. In practical applications, the results of this study can be utilized to support the planning, development, or improvement of U-turn bridge rehabilitation strategies, with an emphasis on techniques that enhance efficiency and safety during execution.

Design and Make a Work Study Simulation Model Using MediaPipe Holistic

Kanyarat Punpain — Fri, 17 Oct 2025 00:00:00 +0700

This research aimed to design and develop a work simulation set using MediaPipe Holistic to assess fatigue, improve the accuracy of time recording, and measure body movement angles during task performance, thereby addressing issues of manual timing errors and limitations in fatigue evaluation. Testing was conducted in two configurations: Configuration 1 used a tray positioned 42 cm away with a chair height of 62.8 cm, while Configuration 2 used a tray positioned 27.5 cm away with a chair height of 54.8 cm. The study found that Configuration 1 was more effective at reducing fatigue than Configuration 2, primarily due to minimizing torso twisting; however, both configurations still resulted in shoulder and arm pain with continuous work. Standard time analysis with MediaPipe Holistic revealed that Configuration 1 had an average of 9.89 seconds per piece and demonstrated more continuous movement, whereas Configuration 2 had an average of 9.91 seconds per piece and emphasized greater shoulder flexibility. This finding is valuable for designing ergonomic workstations to enhance efficiency and reduce fatigue.

Development of a Community-Based Business Model Utilizing Solar Energy and Net Metering: A Case Study of Community Enterprises in Chanthaburi Province, Thailand

Kornpaphop Ruttanawijit, Artit Kamtai, Kritsana Chanthasit — Fri, 17 Oct 2025 00:00:00 +0700

This study aims to design and develop a community energy business model by applying a solar photovoltaic (PV) system with Net Metering to reduce energy expenses among community enterprises in Chanthaburi Province. The research employed a mixed-methods approach, including a twelve-month retrospective analysis of electricity bills and in-depth interviews with 15 target community groups across both urban and rural areas. Statistical analysis revealed that rural community enterprises had a higher average energy cost of 5.20 THB/kWh compared to 4.50 THB/kWh in urban areas, primarily due to outdated technology and inadequate infrastructure.
Cluster analysis using K-Means classified the enterprises into two groups; Cluster 0 (low energy use with high costs) and Cluster 1 (high energy use with high costs), providing insights for designing tailored energy and technology strategies. The business model was developed using the Business Model Canvas (BMC) framework, covering nine core components. An economic feasibility assessment of the Net Metering system showed a levelized cost of electricity (LCOE) at 2.21 THB/kWh, significantly lower than the regional utility rate of 4.10 THB/kWh. The internal rate of return (IRR) was approximately 13.5%, affirming the investment’s viability and its potential scalability to other communities with similar contexts. Importantly, community participation was identified as a key factor for ensuring the long-term sustainability of decentralized energy systems.

Development of Domestic Cooking Burner using Stainless Wire - Mesh Porous Media

Fri, 17 Oct 2025 00:00:00 +0700

This research aims to improve the thermal efficiency of domestic cooking burner, of which the highest amount of Liquefied Petroleum Gas (LPG) consumes not excess 5.78 kW, in accordance with Thailand Industrial Standard (TIS 2312-2549). Many plates of stainless wire - mesh were packed as the new cooking burner and was called stainless wire - mesh porous of domestic cooking burner (SWB). In the experiment, three pores per inch (PPI) of wire-mesh consisting of 8, 12 and 16 were conducted. Two fuel rates (Q_F) of 2 and 3 kW were conducted. Two thicknesses of stainless wire - mesh (H = 1 and 2 cm) were examined. The experimental results of six SWBs were compared with two conventional gas cooking burners, i.e., radial slotted gas burner (RB) and honeycomb porous ceramic burner (PB). From the experiment, it was found that the boiling time of water was faster than the level of thermal efficiency (Ƞ_th) in SWB was also higher than PB and RB in all experimental conditions. In comparison for SWB, the Ƞ_th of SWB at H = 1 cm had a similar to the case of H = 2 cm. The SWB constructed by the SWB08-01 (PPI=8), yielded the maximum level at 52.16 % at Q_F = 2 kW. In addition, remarkably, the levels of CO and NO_X of the six SWB were relatively low. The values will be low, not exceeding 220 and 45 ppm, respectively.

Success Factors in Construction Management of Local Administrative Organizations in Mueang District, Phetchabun Province: an Exploratory Factor Analysis

Pattana Suwansumrit, Jakrapong Pongpeng — Fri, 17 Oct 2025 00:00:00 +0700

This study aims to examine the success factors in construction project management of local administrative organizations in Mueang District, Phetchabun Province, using Exploratory Factor Analysis (EFA). The sample consisted of 240 respondents from both public and private sectors. A questionnaire was employed as the research instrument, and data were analyzed using descriptive statistics, EFA, and the Mann-Whitney U test for comparing group perceptions. The findings revealed four major groups of success factors: (1) overall project management, (2) scope and risk management, (3) core objective management, and (4) supportive management functions, comprising a total of 12 sub-factors. Additionally, significant differences in perspectives between the public and private sectors were identified in several aspects. These findings highlight the importance of designing construction management systems that account for sector-specific characteristics to enhance the efficiency and sustainability of local projects