Teknomekanik

Enhancing heat transfer performance of automotive car radiator using camphor nanoparticles: experimental study with bibliometric analysis

Wed, 04 Oct 2023 00:00:00 +0000

In this study, an attempt was made to investigate the heat transfer performance of a four-wheeler automotive radiator using a novel coolant system. To support this study, we also added bibliometric analysis to show the importance of this study. In the experiments, camphor nanoparticles (sizes of 511 nm) with various loadings (i.e. 2, 4, 6, and 8%) were mixed with deionized water (DW) to create a coolant. The experiments were conducted at different heat convection processes (i.e. 0.5, 1.45, and 3.7 m/s). The significant heat transfer performance parameters, such as Reynolds number (Re), Nusselt number (Nu), overall heat transfer coefficient (U), and heat transfer rate (Q), were examined. The Fourier Transform Infrared results revealed the presence of significant functional groups in the coolant system. camphor nanoparticles dispersed in DW were stable for more than 8 hours. At 70 ᵒC, the novel coolant (2% camphor nanoparticles in DW) exhibits better Re, Nu, U, and Q than that using pure DW or other loadings of nanoparticles (e.g. 4, 6, and 8%). The high percentage of camphor nanoparticles in DW restricts the fluid flow, resulting in a drop in overall heat transfer performance. Finally, low-cost, easily available, and eco-friendly camphor nanoparticles (2%) are suggested as a better choice in lieu of high-cost metallic and non-metallic nanoparticles as an additive in the coolant system.

Experimental investigation of effect of extent and position of bypass openings on performance of a single unit liquid desiccant based indirect evaporative cooler

Pamu Raja Naveen, Srinivas Kishore Pisipaty, Siva Subramanyam Mendu (Author) — Fri, 03 Nov 2023 00:00:00 +0000

In high temperature and high humidity zones, evaporative cooling is ineffective and vapour compression systems are less energy efficient. Therefore, an alternative system is highly desirable which is effective, energy efficient and enables the use of cheap and sustainable energy sources. Indirect evaporative cooling helps in retaining humidity level of air, but is less effective in attaining lower air temperatures. To mitigate this challenge, M-cycle indirect evaporative cooling system helps in achieving sub-wet bulb temperatures. In this work, performance of a novel modified indirect evaporative M-cycle cooling system assisted by 40% aqueous Li-Cl liquid desiccant is experimentally investigated against various parameters. The cooling system used in this study is a single unit system which can perform indirect evaporative cooling, liquid desiccant dehumidification and internal cooling to the liquid desiccant. With an air velocity of 1 m/s at the inlet, the introduction of openings in between inlet and exit of the cooling system has shown a maximum improvement of 19.2% in its dew point effectiveness, with unaffected dehumidification effectiveness. Furthermore, it is observed that the dew point effectiveness is decreased with the increasing distance of openings from the inlet. The investigated cooling and dehumidification system is useful as a pre-air-conditioner to conventional air-conditioning systems and also as a stand-alone air-conditioning system.

Enhancing laminate composites: Investigating the impact of kevlar layering and titanium carbide nanoparticles

Adinda Oktaviani, Anne Zulfia, Dieter Rahmadiawan (Author) — Tue, 12 Dec 2023 12:22:29 +0000

The quest for innovative and superior materials is a challenge in the realm of materials science and engineering. Traditional materials often fall short in meeting the demands of modern industries, especially in the military. Technological developments in the military domain are still progressing, one of which involves a new material for combat vehicle applications: a laminated composite. In this research, a composite consisting of AA7075 sheet metal and kevlar with epoxy resin and TiC nanopowder were prepared. A test was conducted to assess its performance in absorbing ballistic energy from projectiles. Solid Thickening Fluid (STF) was created by mixing TiC nanopowder with PEG-400 through 2 hours of stirring. The laminate composite structure was prepared using the hand layup method, followed by a drying process at room temperature. The addition of kevlar layers yielded promising results in the ballistic and impact tests, as the diameter of the perforation decreased progressively with each additional kevlar layer. The IK sample impact test value improved by 35.7% compared to the unimpregnated one. The production process of this material also consumes minimal energy, which suggest a potential for environmental sustainability.

The investigation of physical dan mechanical properties of Nipah-based particle board

Tue, 12 Dec 2023 18:01:50 +0000

The excessive use of wood as a raw material in furniture industries has raised environmental concerns that have attracted the attention of many individuals. Consequently, various innovations have been explored in developing alternative materials for the furniture industry. One promising resource that has the potential to be developed as a raw material for furniture applications is Nipah palm husk. Nipah palm husk is classified as an agricultural waste that is barely used within society and industries. Hence, in this study, Nipah palm husk will be utilized as the primary material to fabricate particle board by involving tapioca as an adhesive. This research aimed to investigate the effect of tapioca concentrations on water absorption, modulus elasticity, modulus of rupture, and screw-holding strength of the produced Nipah palm husk particleboard. The results of this study showed that the particle board produced with a 40% tapioca adhesive concentration exhibited the most favorable physical and mechanical properties with a water absorption rate of 25%, an elastic modulus of 21188.93 kg/cm², a modulus of rupture of 55.53 kg/cm², and a screw holding power of 7.53 kg. The findings indicated that Nipah-based particle board has the potential to be developed as an alternative for the furniture industry.

Numerical study on heat and flow transfer of biomagnetic fluid with copper nanoparticles over a linear extended sheet under the influence of magnetic dipole and thermal radiation

Mohammad Ghulam Murtaza, Maria Akter, Mohammad Ferdows (Author) — Sat, 16 Dec 2023 17:29:39 +0000

A steady, two-dimensional flow of biomagnetic fluid namely blood flow with copper nanoparticles across a stretchable sheet that is affected by a strong magnetic field and thermal radiation is investigated in this study. Copper nanoparticles (Cu-NPs) were used for this study because of their important applicability in biomedical research. Thus, the properties of copper nanoparticles render it an antibacterial, antimicrobial, and anti-fungal material. Similarity substitutions were applied to reduce the nonlinear partial differential equations to ordinary differential equations. Utilizing the MATLAB R2018b software bvp4c function technique, the physical solution was established. This model's pertinent dimensions, such as the ferromagnetic parameter, the magnetic field parameter, the radiation parameter, the suction parameter, the ratio parameter, the slip parameter, and the Prandtl Number, were computationally and graphically inspected about the dimensionless velocity, temperature, skin friction, and heat transfer rate. One of the pivotal observations was that a rise in the ferromagnetic parameter and Prandtl number drops the temperature and velocity, correspondingly. A cross-case analysis with the outcome of other published research is also executed for divergent parameter values. Based on the investigations, copper nanoparticles may be advantageous for biomedical purposes and lessen the hemodynamics of stenosis. Owing to the research, copper nanoparticle-concentrated blood exhibits a reduced flow impedance and a larger temperature changeability compared to sheer blood.

The effectiveness of the multi-soil-layering system in reducing pollutant parameters of crumb rubber industrial wastewater

Sun, 17 Dec 2023 05:41:18 +0000

Multi-soil-layering (MSL) is well-known as an emerging technology for wastewater treatment. However, limited studies have been conducted on the crumb rubber industry. Thus, this study aims to reduce the crumb rubber industrial wastewater using MSL system. Four models of MSL conducted it. They are (1) constructed by body size of gravel with a mixture of andosol soil and fine charcoal; (2) body size of gravel with a mixture of andosol soil, fine charcoal, sawdust, and iron particles; (3) tube size of gravel with a mixture of andosol soil and fine charcoal; and (4) tube size of gravel with a mixture of andosol soil, fine charcoal and sawdust. The construction models were installed in the variance of the box and each of them was flowed by the Hydraulic Loading Rate of wastewater. Aeration treatment is given to the maximum hydraulic loading rate. The result showed that MSL systems significantly minimize the crumb rubber industrial wastewater under requirements that cover Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), Total Nitrogen (T-N) and Total ammonia (T-NH₃). It also significantly neutralizes the power of Hydrogen (pH) up to 6. The highest reduction was obtained by the MSL 3 system (tube size of gravel with a mixture of andosol soil and fine charcoal). The aeration significantly decreased the BOD, COD, TSS, and ammonia from 85% to 99%. Although the aeration process enhanced the performance of MSL system, however, MSL without aeration successfully treated the wastewater to meet the required standard. This study provides new insight into the effectiveness of MSL system in reducing pollutant parameters of crum rubber industrial wastewater.

Comparison of variation in the building shapes and the window-to-wall ratio by concerning energy consumption for thermal comfort and lighting

Wed, 20 Dec 2023 09:23:22 +0000

: Currently, an influential factor contributing to thermal comfort home design is the incorporation of energy-efficient passive design principles. It is exemplified by strategic window placement, the utilization of thermally efficient materials, and effective insulation. It exerts a substantial influence on thermal comfort and electrical consumption. This paper examines the effect of building shape and window-to-wall ratio (WWR) on thermal comfort and lighting energy consumption in residential houses in tropical climates. The lighting electricity and the adaptive thermal discomfort hours of 30 different models of houses were obtained using OpenStudio and EnergyPlus simulation software. The models were developed for three building shapes (square, rectangle, and L-shaped), and each model was varied in five models of window-to-wall ratios. Results indicate that the square-shaped model with a WWR of 10% will provide the lowest energy consumption in thermal comfort had 420.45 kWh/m². On the other side, the lowest energy consumption in lighting is the square-shaped model with a WWR of 50% had 507.95 kWh/m². Thus, the recommendation is to use the square-shaped house that represents the most efficient air conditioning system while the other WWR set also produce the most natural luminaire. It is because the percentage of WWR increased will result in more energy consumption in air cooling but slightly lower energy consumption in lighting. However, when considering aesthetics and freshness, the WWR of the 50% model will offer a better deal.