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This research aims to analyze the influence of thermal conditions; specifically the temperature difference between the test object and the environment; on the characteristics of air flow and heat transfer around it. The object of this study is a test piece subjected to free air flow under various temperature conditions; focusing on the convection heat transfer phenomenon. The main problem addressed is how temperature variations affect the convection heat transfer coefficient; heat transfer rate; and heat flux; as well as changes in air velocity and pressure profiles. Therefore; the objective of this research is to quantitatively compare and assess these thermal and fluid parameters through an experimental study approach and Computational Fluid Dynamics (CFD) simulation. The methodology involves direct measurement of temperature and pressure parameters under low and high-temperature conditions; which are then processed to determine the convection coefficient (); heat transfer rate (); and heat flux (). The main findings indicate that at low-temperature conditions; the heat transfer coefficient () was found to be 53.26 ; the heat transfer rate () was 24.99 W; and the heat flux () was 537.87 ; with a pressure drop of 0.86 Pa. In conclusion; thermal conditions play a crucial role in determining the dynamics of air flow and the efficiency of heat transfer; the greater the temperature difference (); the higher the potential heat transfer rate; establishing a strong correlation between thermal conditions and the convection phenomenon.

separating and shredding organic and inorganic waste. This study aims to analyze the process of shredding household waste using the Computational Fluid Dynamics–Discrete Element Method (CFD-DEM) and determine the optimal operational parameters based on variations in rotor speed. The research method uses numerical simulation with SolidWorks 2024 software for geometric modeling and Ansys Rocky 2023 R1 for CFD-DEM simulation. The rotor speed variations used are 1000 RPM, 2500 RPM, and 4000 RPM with a mass flow rate of 4 tons/hour and a simulation duration of 2 seconds. The parameters analyzed included particle mass flow rate, shredding characteristics, and power consumption. The simulation results showed that a speed of 1000 RPM produced the most optimal performance with a maximum capacity of ±4 tons/hour and a stable shredding response compared to other variations. At 2500 RPM, there were high fluctuations with low capacity (±0.6 tons/hour), while at 4000 RPM, the capacity was moderate (±1.1 tons/hour) but still did not exceed the performance of 1000 RPM. Based on these results, it can be concluded that a rotor speed parameter of 1000 RPM is the most effective condition for improving the grinding efficiency and production capacity of a hammer mill-type Depackaging machine based on CFD-DEM simulation.

PT UVW uses jigs in the vacuum metalizing process that require washing, which is currently done manually, resulting in inefficiency and risks to operators, thus, jig washer machine was created in order to reduce the risk for operators and increasing efficiency, which based on horizontal mixer. This study analyses the effect of agitator design on fluid flow patterns in a jig washing machine to obtain an optimal design. Two agitator design alternatives were developed and tested using Computational Fluid Dynamics (CFD) simulations at rotational speeds of 70, 75, and 100 rpm, followed by prototype fabrication and performance testing. Simulation results show that the second design produces a higher fluid velocity (20.4 m/s) and a more turbulent and uniform flow pattern compared to the first design (1.7 m/s). Field tests confirmed that the second design achieves higher washing effectiveness (97.14%) with reduced water consumption and shorter washing time. The optimally designed agitator washing machine increases productivity by six times compared to manual washing and reduces operator exposure to hazardous chemicals. This study recommends the second agitator design for improving washing efficiency and effectiveness.

Coffee husk is an agro-industrial waste with significant potential to be utilized as a renewable energy source through the fast pyrolysis process. This study aims to analyze and optimize gas production from the fast pyrolysis of coffee husk biomass using a screw reactor through single-particle-based Computational Fluid Dynamics (CFD) simulations. The simulations were conducted by varying the operating temperature at 500°C, 600°C, and 700°C to examine pressure distribution, heat transfer, particle temperature, and the formation of pyrolysis products, namely bio-oil, biogas, and biochar. The modeling was performed using COMSOL Multiphysics 6.2 with a numerical approach to represent thermal phenomena and biomass decomposition reactions during the pyrolysis process. The simulation results indicate that increasing temperature significantly affects the rate of heat transfer and the temperature distribution of coffee husk particles. At 600°C, heat transfer and temperature distribution are more uniform compared to 500°C, although heating at the particle core is not yet fully optimal. The pressure distribution shows a stable flow of pyrolysis gas from the bottom to the top of the reactor. In terms of products, increasing temperature leads to a reduction in biochar and bio-oil formation due to the occurrence of secondary reactions, while biogas production increases. The highest gas production is achieved at 700°C, indicating the most optimal condition for maximizing gas yield from fast pyrolysis. Therefore, single-particle-based CFD simulation can be used as an effective tool to understand pyrolysis mechanisms and optimize process parameters in a screw reactor.

This study aims to analyze the direct, indirect, and subsequent impacts of Car Free Day (CFD) activities in Labuhan Badas Sub-district, Sumbawa Regency. The approach used is Multiplier Effect Analysis, which utilizes multiple effects based on real conditions in the field. In addition, this study also evaluates the perceptions of the community, labor, and businesses towards CFD activities with Descriptive Statistical Analysis, specifically through the Chi-Square Test. The data used is primary data, obtained through direct interviews with relevant respondents. With primary data collection and qualitative analysis, multiplier effect calculations can be performed. The results of the Multiplier Effect analysis show that the Keynesian Income Multiplier is 2.43, which means that every additional public expenditure of one rupiah can increase income by around 2.43 rupiah. In addition, the Income Multiplier Ratio of 1.06 indicates that every investment of one rupiah in CFD-related business units will result in an increase in income of 1.06 rupiah, including both direct and indirect impacts. Based on these results, the Multiplier Effect Analysis of CFD in Sumbawa Regency succeeded in achieving the research objectives, namely knowing the impact of Car Free Day activities on the local economy.

Kenyamanan termal dalam ruangan sangat penting untuk efektivitas kinerja pengguna ruang, terutama bangunan masjid yang digunakan untuk beribadah oleh banyak orang. Sistem peghawaan alami yang memanfaatkan aliran udara dan desain fasad yang baik sangat berperan dalam menciptakan lingkungan yang nyaman. Penelitian ini bertujuan untuk mengoptimalkan fasad Masjid Quwwatul di Yogyakarta guna mencapai kenyamanan termal. Metode simulasi menggunakan perangkat lunak Autodesk CFD untuk mengukur kecapatan udara sebagai variabel kenyamanan termal, dan menggunakan CBE untuk mengukur kenyamanan termal pada ruang ibadah. Hasil menunjukkan bahwa fasad eksisting belum mencapai kenyaman termal, dengan aliran udara masuk hanya sebesar 0,74 m/s. Alternatif desain fasad diperlukan untuk meningkatkan aliran udara. Alternatif 1 dapat meningkatkan aliran udara menjadi 1,22 m/s dengan memperbesar bukaan sebesar 13% dan menggunakan sistem ventilasi silang, sehingga dikategorikan sebagai nyaman hangat. Alternatif 2 dapat meningkatkan aliran udara menjadi 1,3 m/s dengan memperbesar bukaan sebesar 19% serta menggunakan sistem bodycooling dan ventilasi silang, sehingga masuk ke dalam kategori nyaman hangat.

This study aims to analyze the temperature distribution in an LPG-fueled chili drying machine using Computational Fluid Dynamics (CFD) simulation. The simulation was performed using SolidWorks Flow Simulation 2022 to investigate the effect of inlet air temperature and velocity on temperature uniformity inside the drying chamber. Three inlet temperature variations were applied: 60°C, 70°C, and 80°C, combined with two air velocities of 10 m/s and 11 m/s. The results showed that these parameters significantly influence temperature distribution. The optimum condition was achieved at 70°C and 10 m/s with a temperature uniformity efficiency (

This study aims to analyze the temperature distribution in an LPG-fueled chili drying machine using Computational Fluid Dynamics (CFD) simulation. The simulation was performed using SolidWorks Flow Simulation 2022 to investigate the effect of inlet air temperature and velocity on temperature uniformity inside the drying chamber. Three inlet temperature variations were applied: 60°C, 70°C, and 80°C, combined with two air velocities of 10 m/s and 11 m/s. The results showed that these parameters significantly influence temperature distribution. The optimum condition was achieved at 70°C and 10 m/s with a temperature uniformity efficiency (

The air quality index in Depok City has declined over the past three years based on data from the Depok City Environmental Agency. In response to this condition, the Depok City Government implemented a Car Free Day (CFD) policy every Sunday along Jalan Margonda Raya. The CFD program aims to improve environmental quality and air conditions while encouraging public participation in healthy activities. The success of this policy depends on how effectively information regarding the rules and objectives of CFD is disseminated to the public by the Depok City Government Public Relations Office. This study aims to analyze the communication strategy employed by the Depok City Government Public Relations Office in disseminating the Car Free Day policy and to identify obstacles encountered during the dissemination process. This research uses a descriptive qualitative approach through media monitoring, direct observation, and analysis of government documents.

Steam turbines remain a core technology in thermal power generation and continue to evolve through advances in aerothermal design, materials, control strategies, and digital maintenance. This paper presents a systematic literature review (SLR) of recent international studies published between 2020 and 2025 to synthesize current developments in steam turbine performance and thermal efficiency improvement. Article identification was conducted through SCOPUS using keywords related to turbine efficiency, blade/nozzle optimization, failure analysis, and material enhancement. The selected studies were analyzed thematically across four domains: (1) design and optimization using CFD/FEA, (2) material and structural resilience, (3) operational performance under variable/part-load conditions, and (4) integration with hybrid renewable systems and predictive maintenance. The reviewed evidence indicates that CFD-based nozzle/blade optimization and advanced control approaches can yield measurable efficiency improvements (approximately 2–7.3%), while material innovations and enhanced cooling strategies improve durability by mitigating thermal stress and fatigue risks. In parallel, digitalization through IoT-based predictive maintenance and additive manufacturing is increasingly reported as a pathway to reduce downtime and accelerate component production. However, recurring gaps include limited real-world validation, insufficient studies in humid/tropical environments, and a lack of long-term economic/lifecycle assessments. Future work should prioritize experimental or field verification, region-specific performance studies, and integrated techno-economic evaluation to support broader deployment of high-efficiency steam turbine systems.

The growing demand for energy-efficient and intelligent thermal systems has driven significant advancements in adaptive compressor design. This paper presents a comprehensive literature review on the development of AI-based compressor systems, with a specific focus on enhancing efficiency under partial-load conditions and optimizing the utilization of residual energy. Through the synthesis of five recent high-impact studies (2020–2025), we examine the application of deep reinforcement learning (DRL), hybrid evolutionary algorithms, and neural network surrogate modeling in compressor optimization. Key findings indicate that model-based DRL combined with surrogate CFD can achieve up to 8% efficiency gains at off-design conditions. Hybrid approaches integrating Genetic Algorithms (GA) with DRL reduce optimization time by 30% while improving pressure ratios. Neural network surrogates provide high-speed, real-time performance predictions with less than 1% error, enabling mass iterative design. Furthermore, intelligent load classification using radial basis function networks (RBFN) allows adaptive response to varying operating conditions with over 95% accuracy. Collectively, these methods form a framework for intelligent, self-optimizing compressor systems capable of real-time adaptation and energy recovery. The results suggest that AI-enhanced adaptive compressors represent a transformative direction for energy-sensitive sectors, including HVAC, power generation, and sustainable industry.

The fraud case that struck PT CFD Traveller Sukabumi shook the company’s reputation and threatened its relationship with customers, triggering a crisis. This study aims to examine the crisis management of Public Relations at PT CFD Traveller Sukabumi in dealing with the 2024 fraud case, as well as to identify its opportunities and challenges. The research employed a qualitative approach with a descriptive analysis method. Data were collected through in-depth interviews with key informants and individuals directly involved in crisis management. The study applied Coombs and Holladay’s theory, identifying the stages of pre-crisis, crisis, and post-crisis. At the pre-crisis stage, the company conducted risk analysis and careful planning, including communication procedures and employee training. At the crisis stage, the company implemented the plan quickly and in a coordinated manner through clear and open communication with the public and by maintaining good relations with the media to ensure accurate information. At the post-crisis stage, the company carried out comprehensive evaluations, updated its crisis management plan, engaged consumers in the recovery process, and launched campaigns emphasizing customer safety and satisfaction. The findings highlight that structured crisis communication strategies play a crucial role in maintaining public trust.

Black Soldier Fly (BSF) larvae, or maggots, are a type of insect currently widely cultivated, primarily for animal feed. This is because BSF larvae contain essential nutrients such as fat and protein in high amounts, thus improving the nutritional quality of livestock that consume them. Therefore, the processing and preservation of maggots is crucial to maintain their nutritional content and extend their shelf life. One method used in maggot processing is drying. Drying aims to reduce the water content in the larvae, thereby preventing the growth of microorganisms that cause spoilage. One widely applied technique is drying using a microwave oven. However, before the actual process is carried out, simulations are often required to determine the distribution of heat and humidity. Simulation is one of the most effective ways to predict the drying performance of biological materials. This study used a simulation using the Computational Fluid Dynamics (CFD) method operated by Comsol Multiphysics 6.2 software. The parameters used in the simulation were an initial maggot temperature of 80°C, a drying time of 15 minutes, and a heat source of 1300 W/m³. Based on the simulation results, the final water content of the maggots was below 10%. Furthermore, the final relative humidity of the maggots ranged from 10–35%, while the final temperature of the larvae increased to 93–97°C. These results indicate that microwave drying can effectively reduce moisture content while maintaining the nutritional quality of BSF larvae. These simulation results can be used as a basis for practical maggot drying processes, thus supporting the production of efficient and nutritious animal feed.  

Cough and flu are common health problems experienced by the public, with high prevalence across various age groups. The widespread practice of self-medication in the community highlighted the need for proper education regarding the rational and appropriate selection of medications. This educational activity was conducted at two strategic locations: the Car Free Day (CFD) in Solo and Taman Jaya Wijaya in Mojosongo. The method involved direct socialization, distribution of educational leaflets, and interactive question-and-answer sessions. The education focused on the differences between dry and productive coughs, appropriate medication choices, flu medicine content, and the use of natural remedies such as herbal treatments. A total of 41 participants from diverse backgrounds joined the activity enthusiastically. The results showed an increase in public understanding of cough classifications, medicine components, and the importance of reading drug labels before purchase. The sessions also emphasized the need to match medications with symptoms and advised consulting healthcare professionals if symptoms did not improve within three days. Positive responses from participants indicated that direct education effectively raised awareness and encouraged more rational and safe self-medication practices.

Cough and flu are common health problems experienced by the public, with high prevalence across various age groups. The widespread practice of self-medication in the community highlighted the need for proper education regarding the rational and appropriate selection of medications. This educational activity was conducted at two strategic locations: the Car Free Day (CFD) in Solo and Taman Jaya Wijaya in Mojosongo. The method involved direct socialization, distribution of educational leaflets, and interactive question-and-answer sessions. The education focused on the differences between dry and productive coughs, appropriate medication choices, flu medicine content, and the use of natural remedies such as herbal treatments. A total of 41 participants from diverse backgrounds joined the activity enthusiastically. The results showed an increase in public understanding of cough classifications, medicine components, and the importance of reading drug labels before purchase. The sessions also emphasized the need to match medications with symptoms and advised consulting healthcare professionals if symptoms did not improve within three days. Positive responses from participants indicated that direct education effectively raised awareness and encouraged more rational and safe self-medication practices.

Air circulation and natural lighting are among the key aspects influencing the comfort of room usage, particularly in dormitory buildings inhabited by university students. This study aims to explore thermal comfort more deeply, focusing on air circulation and natural lighting within student dormitory rooms in the Riau Islands. A qualitative method was employed, collecting up-to-date data on the selected building. Building simulations using Computational Fluid Dynamics (CFD) and DIALux were conducted to analyze the speed of air circulation and the quality of natural lighting within the rooms. The results reveal that prior to evaluation, the dormitory rooms faced thermal issues related to poor air circulation and insufficient natural lighting. Wind speed was recorded at less than 2 m/s, and the incoming and outgoing airflow collided due to the presence of only one ventilation access. The evaluation using cross-ventilation through room openings showed a positive impact on indoor air circulation, increasing wind speeds to 2–4 m/s. The cross-ventilation concept also enhanced the discharge and exchange of indoor air, preventing air stagnation. In terms of natural lighting, the simulation showed that lighting intensity in several rooms was below the minimum standard of 250 lux, particularly in areas far from the window openings. After modifications to the window layout and the addition of secondary light-transmitting elements, the lighting level significantly improved to meet the recommended standard. These findings highlight the importance of incorporating both passive ventilation and natural lighting strategies in student dormitory designs. Improving these environmental aspects not only enhances thermal comfort but also supports the health, productivity, and well-being of the residents. This study contributes to the growing body of research on sustainable dormitory design and can be used as a reference for future architectural planning and policy improvements.

This study aims to analyze the performance and conduct reverse engineering of the Francis Turbine runner at the Tanggari 1 Hydroelectric Power Plant (PLTA Tanggari 1) through 3D scanning and Computational Fluid Dynamics (CFD) simulation. The main objective is to evaluate the turbine's efficiency and identify areas for improvement in the runner geometry. Data from the 3D scan are used to reconstruct a CAD model, which is then numerically tested to predict hydraulic performance. CFD simulations are carried out under various guide vane openings and head variations. The simulation results show a maximum efficiency of 93% at a head of 122.4 meters with a guide vane opening angle of 26° and a flow rate of 8.5 m³/s. The resulting performance curve and hill chart indicate the optimal operating point or Best Efficiency Point (BEP), which serves as a critical reference for turbine operation settings. Flow phenomena such as separation and vortex formation were detected under off-BEP operating conditions, potentially causing pressure fluctuations and vibrations. As a technical recommendation, it is advised to operate the turbine close to the BEP to minimize vibrations and energy losses. Furthermore, the runner geometry obtained from reverse engineering can serve as a basis for component refabrication and the development of new runner designs that are more adaptive to varying load conditions.

Maggots are larvae of the Black Soldier Fly (BSF) which have benefits as waste decomposers and have high potential as feed ingredients. This study aims to analyze the effect of power and time on maggot drying using microwaves. Using the Computational Fluids Dynamics (CFD) method on microwave heating with a power of 2000 watts and 2500 watts, and a residence time of 10 minutes, 20 minutes, and 30 minutes, then the final maggot temperature was tested. The results showed that the final temperature of the maggot tended to increase with increasing power and residence time. This happens because high microwave power provides large energy in a very short time. This energy is efficiently absorbed by maggots through the mechanism of dipole rotation and ionic conduction, causing molecules to vibrate and rub with high intensity. The final temperature of the maggot is between 110oC-125 oC with the highest temperature at a power of 2500 and a drying time of 30 minutes.

The incidence of out-of-hospital cardiac arrest increased (OHCA) significantly. The survival rates of OHCA would be decreased 7-10% every minutes. Therefore, the patients with OHCA must be performed cardiopulmonary resuscitation (CPR) immediately. However, CPR is commonly not performed due to lack of knowledge, skills and fair of being transmitted of diseases. Hands Only CPR (HOCPR) is designed for lay rescuer through two simple steps, firstly call the nearest health center, secondly performed compression to the middle of chest. This socialization aimed to improve knowledge and willingness of lay rescuer to perform HOCPR.  This socialization has been done in CFD Samota Sumbawa on 18th  June 2023. More than 100 flayers have been distributed followed by discussion regarding the importance of CPR. The result of the outreach showed that visitor of CFD Samota were very enthusiastic and they were able and willing to perform HOCPR. Therefore, health care centers, such as hospitals, university and organizations related to emergency sector need to actively provide outreach and demonstrations related to HOCPR.

Indonesia, as the world's largest archipelagic nation, holds a strategic position while simultaneously facing significant challenges in maintaining the sovereignty and security of its maritime territory. Increasingly complex maritime threats, such as illegal fishing, smuggling, and potential geopolitical conflicts, demand a transformation in maritime defense strategies to be more efficient and sustainable. In an era of increasing global awareness of the climate crisis, the maritime sector, including the defense sector, is being encouraged to decarbonize through the implementation of environmentally friendly ship technology. This research uses a literature review approach by examining various findings related to sustainable propulsion technology innovations relevant to the development of Indonesia's maritime defense fleet. The study results show that a hydrogen- and battery-based hybrid propulsion system can reduce carbon emissions by up to 73% and increase energy efficiency by 35%. In addition, wind-assisted propulsion sistem (WAPS) technology such as Flettner rotors and wing-sails contributes significantly to reducing fuel consumption by up to 30%, while extending ship cruising range without the need for intensive refueling. Meanwhile, the application of Computational Fluid Dynamics (CFD)-based propeller design optimization has been proven to reduce energy consumption by 13.2% and reduce noise levels by up to 15 dB, which greatly supports the needs of stealth operations in military missions. This study concludes that the implementation of environmentally friendly ship technology not only provides benefits in terms of energy efficiency and emission reduction, but also strengthens the operational resilience and strategic competitiveness of the Indonesian naval fleet amidst the dynamics of global maritime security. Thus, the Green Navy concept can be seen as a relevant and urgently needed sustainable defense strategy.