Analysis Effects of Average Value of Convective and Evaporative Heat Transfer Coefficient on Solar Cabinet Dryer for Reduction of Mass of Papad

In this research paper, the behavior of heat and mass transfer phenomenon during greenhouse papad drying under forced convection mode has been investigated. Various experiments were performed during the month of April 2020 at SRCEM Banmore, morena (26o 34’13” N 78o 10’48” E). Experimental data obtained for forced convection greenhouse drying of papad were used to determine the constants in the Nusselt number expression by using the simple linear regression analysis and, consequently, the values of convective and evaporative heat transfer coefficients were evaluated. The average values of experimental constants C and n were determined as 0.9714 and 0.0129 respectively. The average values of convective and evaporative heat transfer coefficients were determined as 0.0886 W/m2 oC and 6.7583 W/m2 oC respectively. The experimental error in terms of percentage uncertainty was also evaluated. Keywords: Papad, Papad drying, Heat transfer coefficient, Convective, Evaporative, Forced convection greenhouse

Influence of fully submerged permanent magnets in the evaluation of heat transfer and performance analysis of single slope glass solar still

In this experimental study, permanent magnets with three different sizes (M-1: 32 mm inner diameter, 70 mm outer diameter and 15 mm thick, M-2: 25 mm inner diameter, 60 mm outer diameter and 10 mm thick, M-3: 22 mm inner diameter, 45 mm outer diameter and 9 mm thick) are fully submerged in the single-slope glass solar still. The performance of magnetic solar stills (MSS) with three different sizes at 2 cm depth water to ensure that magnets are fully submerged is compared with conventional solar still (CSS) at the location 17.3850°N, 78.4867°E. Tiwari model is adapted to calculate the heat transfer coefficients (HTC), internal and exergy efficiencies. MSS with M-1, M-2 and M-3 significantly enhanced the convective, radiative, and evaporative heat transfer rate for the 2 cm depth of water. This is due to the desired magnetic treatment of water, which reduces the surface tension and increases the hydrogen bonds. The MSS's total internal HTC, instantaneous efficiencies led CSS by 25.52%, 28.8%, respectively, with M-1. Having various magnetic fields due to different magnets sizes increases MSS's exergetic efficiency by 33.61% with M-1, 33.76% with M-2, and 42.25% with M-3. Cumulative yield output for MSS with M-1, M-2, and M-3 is 21.66%, 17.64%, 15.78% higher than CSS. The use of permanent magnets of different sizes in the MSS is a viable, economical and straight forward technique to enhance productivity.

Analisa Energi pada Alat Desalinasi Air Laut Tenaga Surya Model Lereng Tunggal

<p class="Abstract">The use of solar energy every day is increasing due to the greater human need for energy. the application of solar desalination equipment is classified as a renewable technology that is very profitable because the energy used is obtained for free and does not cause damage to the environment. This study examines the performance of the solar desalination device with a single slope model with a passive system. It is hoped that greater energy absorption is expected to accelerate the process of evaporation of seawater in the evaporator so as to produce lots of clean water. The desalination tool on the surface of the wall is insulated using aluminum foil with a thickness of 20 mm. The highest solar intensity was obtained on the fifth day of testing, namely 420.85 W/m² with the radiation heat transfer coefficient of 18.44 W/m^{2 o}C, and the lowest solar intensity on the second day, namely 96.89 W/m² with the lowest total outside heat transfer coefficient of 25.57 W/m^{2 o}C. The highest evaporative heat transfer coefficient is 10.54 W/m^{2 o}C and the lowest is 4.42 W/m² ^oC. the lowest energy absorbed by the evaporator on the second day was 1.37 kWh. And the highest efficiency on the fifth day reached 58.89% and the lowest energy efficiency on the second day, namely 34.05%.</p>

Development and characterization of warp knitted spacer fabrics for helmet comfort liner application

The inner padding layer of the motorcycle helmet is one of the important components that control the factors of comfort during wearing the helmet and provides a perfect fit and stability of the helmet on the head. The inner padding consists of a low-density flexible polyurethane layer attached to a soft fabric layer that is in direct contact with the head. The present study aims to replace foam in the comfort liner of a helmet with spacer fabrics to avoid the risk of heat stress during the use of the helmet. In this work, 9 warp-knitted spacer fabrics were produced by varying the course/cm (10, 12 & 14) and thickness (3, 3.5, and 4 mm). Air permeability, thermal, and water vapour resistance of the developed spacer fabrics were characterized along with compression properties and compared with commercially available standard liner. The results showed that warp-knitted spacer fabrics had better energy absorption compared to the standard liner. Also, the developed spacer fabrics had better breathability and evaporative heat transfer compared to the standard liner.