Experimental comparison of performance and emission characteristics of 4-stroke CI engine operated with Roselle and Jatropha biodiesel blends

The environmental degradation, combined with the continuous depletion of the world's fossil fuel reserves, has forced the search for alternative fuels. This study was performed to investigate the performance of novel biodiesels in the CI engine. The experiments were performed at three different compressions ratios (16:1, 17:1, 18:1) and four loading conditions (25%, 50%, 75%, 100%). Different types of fuels such as jatropha biodiesel (JB), roselle biodiesel (RB), and ternary biodiesel (TB) were prepared and analyzed. The thermal performance of different fuels was analyzed in terms of brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), and exhaust gas temperature (EGT). The emission characteristics such as CO₂ emission, NO_x emission, and smoke emission were analyzed for all types of fuels. The results of these fuels in the engine were compared with mineral diesel (MD). The BTE was increased with increasing compression ratios and loads for all types of fuels. The BSFC was increased with increasing compression ratios but decreased with increasing loads. The increase in emission of NO_x was observed at higher compression ratios and loads. However, the CO₂ emission was decreased at higher loads and lower compression ratio. The performance curves achieved with a 20% jatropha biodiesel blend showed results that were approximate to those obtained with pure MD. The comparative analysis between different fuels showed that JB exhibit higher thermal performance as compared to other biodiesels. Therefore, JB can be a better alternative to conventional fuel.     

Study of the usability of sinusoidal function heat flux based on enthalpy-porosity technique for PCM-related applications

Journal of Thermal Analysis and Calorimetry - The present study summarizes a two-dimensional (2D) numerical simulation of a phase change material (PCM) melting/solidification processes in a square...     

MHD mixed convection in an inclined cavity containing adiabatic obstacle and filled with Cu–water nanofluid in the presence of the heat generation and partial slip

Journal of Thermal Analysis and Calorimetry - In the present paper, the performance of the graphene oxide in the solar steam generation has experimentally been examined. For this purpose, a setup...     

Modeling and optimization of a proton exchange membrane fuel cell using particle swarm algorithm with constriction coefficient

Journal of Thermal Analysis and Calorimetry - The present study aims at estimating the values of an electrochemical model parameter of a proton exchange membrane fuel cell (PEMFC). A variant of the...     

MHD mixed convection of $$ {\text{Al}}_{2} {\text{O}}_{3} $$ Al 2 O 3 –Cu–water hybrid nanofluid in a wavy channel with incorporated fixed cylinder

Journal of Thermal Analysis and Calorimetry - This study deals with mixed convection of $$ {\text{Al}}_{2} {\text{O}}_{3} $$ –Cu–water hybrid nanofluid in a wavy channel having a...     

Thermal stability of hybrid nanofluid with viscous dissipation and suction/injection applications: Dual branch framework

The thermal stability of nanomaterials is quite necessary for controlling the heat and cooling phenomenon. It is worthy observed that much research has been focused scientists towards the thermal significance of nanoparticles with multidisciplinary engineering and industrial applications. On this end, this report explores the improved thermal mechanism water base material with interaction of hybrid nanofluid stretching and shrinking surface. The cooling and heat phenomenon is observed in presence of viscous dissipation. The hybrid nanofluid characteristics are inspected with combination of copper $\left(Cu\right)$ and aluminum oxide $\left(A{l}_2{O}_3\right)$ nanoparticles with stable prospective. The consideration of such hybrid nanoparticles is due to impressive thermal characteristics and stable thermal performances. Although some studies are focused by researchers on hybrid nanofluid, however the measurement of thermal stability is not claimed yet. The stretching and shrinking configuration specify the porous medium features. The problem is compiled into dimensionless structure which is further preceded via bvp4c scheme. The resultant ODEs are successfully numerically solved using the bvp4c solver technique. Under restricting conditions, numerical findings are compared to previously published results. Non-dimensional profiles of velocity and temperature are shown graphically. Furthermore, graphs and tables show the effects of the physical parameters used on the reduced skin friction and heat transfer rate. Dual branches are found in specified domain of suction factor.     

Evaluating energy efficiency and economic effect of heat transfer in copper tube for small solar linear Fresnel reflector

Journal of Thermal Analysis and Calorimetry - An experimental and numerical investigation of a small linear Fresnel for water heating application has been carried out in Blida, Algeria. The...     

Stability aspect of magnetized hybrid nanofluid with suction and injection phenomenon: Modified thermal model

Nanoparticles with ultra-high thermal efficiency and stability have dynamic applications in numerous eras of thermal sciences, including energy production, heat transmission devices, cooling and heating systems, manufacturing applications, aircraft, and solar energy, among others. This study's primary objective is to investigate the mathematical modeling using a Tiwari and Das nanofluid model, taking into account the effects of magnetic, suction/injection, and thermal radiation, as well as the stability analysis of a hybrid nanofluid containing copper ($Cu$) and alumina ($A{l}_2{O}_3$) nanoparticles in a water-based liquid. Using similarity transformations, self-similarity solutions of the system of governing ordinary differential equations (ODEs) were obtained, and the resulting ODEs were simulated using implementations of the three-stage Lobatto IIIa technique. The numerical results indicate that the energy characteristics such as thermal conductivity increase rapidly when copper nanomaterials are used. It is also noticed that the combination of both nano-materials results in an excellent energy enhancement. For the solution validation, novel stability performances for the obtained simulations are determined.     

Characterization of gold]PMMA hybrid nanomaterials synthesized by hard X-ray synchrotron radiation

In this study, new types of hybrid gold poly（methyl methacrylate） （PMMA） nanomaterials are synthesized. Both PMMA spheres coated with gold nanoparticles and gold nanoparticles coated with PMMA can be synthesized using different ratios of HAuCl4 and MMA precursors, by exposing the mixtures to hard X-ray synchrotron radiation without the use of a reducing agent. According to the photochemical mechanism, gold nanoparticles will precipitate from a solution of HAuCl4 on exposure to synchrotron radiation, followed by the synthesis of PMMA by the polymerization of MMA monomers. These reactions can result in the formation of two different types of new hybrid nanomaterials. When a 1：1 volume ratio of HAuCI4 to MMA is used, we obtain PMMA spheres coated with gold nanoparticles. When a 10：1 ratio of HAuCl4 and MMA is used, we obtain gold nanoparticles coated with PMMA. The hybrid gold/PMMA nanostructures are characterized by transmission electron microscopy, elemental analysis, dynamic-light scattering analysis, gel permeation chromatography and Raman spectroscopy. The hybrid nanomaterials have potential application in the fields of biosensors and drug delivery.