Bio: Hesamoddin Salarian is an academic researcher from Islamic Azad University. The author has contributed to research in topics: Airfoil & NACA airfoil. The author has an hindex of 6, co-authored 26 publications receiving 113 citations.
TL;DR: In this article, a detailed discussion on gasification, biomass fuel characteristics and heat output control of cookstove is presented, along with the impact of supplementary tools on efficiency and emissions.
Abstract: Interest in reducing household energy consumption and indoor air pollutants has increased. Simple devices such as cookstoves are important items in the reduction of the amount of domestic energy consumed in developing countries. This paper summarizes the literature available on biomass cookstoves used in villages of underdeveloped countries to determine their holistic performance, including efficiency and emissions. This is a detailed discussion on gasification, biomass fuel characteristics and heat output control of cookstoves. It reviews cookstove design, performance considerations, materials and geometric parameters along with the impact of supplementary tools on efficiency and emissions. Mathematical modeling and simulations are included and evaluation criteria consisting of testing protocols and performance parameters are compared. An efficiently designed pot can reduce domestic energy consumption, although its impact has been overlooked. Literature concerning the effects of materials and geometrical variables versus heat transfer efficiency of cookware is also discussed. The review addresses the gaps in the literature to pave the way for future research.
TL;DR: In this paper, an integrated structure for liquid hydrogen production using liquid air energy recycling, fuel cells, carbon dioxide power generation cycle, and photovoltaic (PV) panels is developed and exergetically assessed.
Abstract: High specific energy consumption (SEC) and its high cost of manufacturing are among the main problems in the hydrogen liquefaction industry. In this paper, an integrated structure for liquid hydrogen production using liquid air energy recycling, fuel cells, carbon dioxide power generation cycle, and photovoltaic (PV) panels is developed and exergetically assessed. To liquefy the hydrogen gas are utilized six compression refrigeration cycles with hydrogen and helium refrigerants. The compressed liquid air is used for the precooling of the hydrogen liquefaction process. After the cold energy recovery from liquid air, it is heated by the waste heat load of the refrigeration cycle and solid oxide fuel cell (SOFC) and then enters the gas turbine and fuel cell, respectively. The fuel cell output hot stream is used to supply heat to the power generation cycle and preheat the fuel cell inlet stream. This integrated structure generates 1,028 kg/h liquid hydrogen by receiving 60.79 kg/h natural gas and 5.559 MW power from solar panels under the climatic conditions of Yazd, Iran. The specific energy consumption of the hydrogen liquefaction process, SOFC efficiency, and carbon dioxide power generation cycle efficiency are obtained as 5.955 kWh/kgLH2, 62.96%, and 44.06%, respectively. Integrating the refrigeration structure with the process core is performed in the form of hot and cold composite diagrams. The exergy assessment indicates that the highest exergy destruction occurs in solar panels (81.37%), heat exchangers (7.60%), and turbines (4.73%), respectively. The sensitivity analysis demonstrates that the integrated structure exergy and SOFC efficiencies decrease to 52.9% and 62.3%, respectively when the inlet liquid air mass flow rate increases from 7,400 kg/h to 10,200 kg/h. The power supplied by solar panels and SEC of hydrogen liquefaction process increase up to 5,599 kW and 6.1 kWh/kg LH2, respectively with a decrease of pumped liquid air pressure from 80 bar to 40 bar.
TL;DR: In this paper, the aerodynamic performance of the NACA 0012 airfoil under rain and icing conditions was investigated with the aim to better understand the severe aerodynamic penalty of aircraft in flight.
Abstract: In the present study, special attention is paid to numerically investigate the aerodynamic performance of the NACA 0012 airfoil under rain and icing conditions with the aim to better understand the severe aerodynamic performance penalties of aircraft in flight. Furthermore, in order to control the flow separation and improve the aerodynamic performance of the airfoil under critical atmospheric conditions, the Gurney flap with different heights is attached to the trailing edge of the airfoil. The simulation is done at a Reynolds number of 3.1 × 105 under different atmospheric conditions including dry, rain, icing and coupling of rain and icing conditions. A two-way momentum coupled Eulerian–Lagrangian multiphase method is used to simulate the process of water film layer formed on the airfoil surface due to rainfall. According to the results, accumulation of water due to rainfall and ice accretion on the airfoil surface inevitably provides notable negative effects on the aerodynamic performance of the airfoil. It is concluded that icing induces a higher aerodynamic degradation than rain due to very intensive ice accretion. The Gurney flap as a passive flow control method with a favorable height for each condition is very beneficial. The maximum increment of the lift-to-drag ratio is achieved by Gurney flap with a height of 0.01 of airfoil chord length for dry and rain conditions and 0.02 of airfoil chord length for icing and coupling of rain and icing conditions, respectively.
TL;DR: In this paper, the size and performance of a dehumidification tower were studied by simulating varying operating conditions, and a finite difference model was developed to determine the packing height of the tower.
Abstract: In this paper, the size and performance of a dehumidification tower were studied by simulating varying operating conditions. Based on the experimental results, this study presents the performance of a packed tower absorber for a lithium chloride desiccant dehumidification system. The effects of the main variables - airflow rate, liquid desiccant flow rate, and inlet air temperature on the rate of dehumidification were reported. It was found that the influence of these variables could be assumed to be linear. A finite difference model was developed to determine the packing height of the dehumidification towers. This model was worked out in MATLAB code, which is a suitable model for measuring the optimum height of a tower. The validity of this model was compared with published experimental data and our data. Comparisons between the simulated packing height and the actual packing heights used by experimental studies illustrated that our finite difference model is acceptable. With this model, we predict the packing height for every condition, and then we constructed the dehumidifier based on the results of our finite difference model.
TL;DR: In this paper, the effect of hinge position (H) has been numerically investigated to find the appropriate position for improving the aerodynamic performance of the NACA 0012 flapped airfoil.
Abstract: In the present study, the effect of hinge position (H) has been numerically investigated to find the appropriate position for improving the aerodynamic performance of the NACA 0012 flapped airfoil. In addition, perpendicular and tangential suctions have been applied to control the flow separation and enhance the aerodynamic performance over the NACA 0012 flapped airfoil at each different hinge positions. The simulations were carried out at a Reynolds number of 5 × 105 (Ma = 0.021) based on two-dimensional incompressible unsteady Reynolds-averaged Navier–Stokes calculations to determine the adequate hinge position. The turbulence was modeled using the shear stress transport k–ω turbulence model. The effect of perpendicular suction (θjet = − 90°) and tangential suction (θjet = − 30°) was computationally studied over NACA 0012 flapped airfoil for five different hinge positions (H = 0.7c, 0.75c, 0.8c, 0.85c and 0.9c) and a flap deflection (δf) of 15°. Based on the results, the hinge position significantly affects the aerodynamic performance of the airfoil. The lift coefficient increased clearly as the hinge position moved to the trailing edge of the airfoil. Using perpendicular suction caused to increase the lift coefficient and decrease the drag coefficient. Consequently, the maximum value of the lift-to-drag ratio (CL/CD) for perpendicular and tangential suctions was achieved about 35.8% and 25.1% higher than that of the case without suction at an angle of attack of 12° and H = 0.9c. Also, the effect of perpendicular suction was more considerable compared to the tangential suction. This caused a reduction in the size of the recirculation zone from 0.5 to 0.09 of the airfoil chord length and also transferred it from 1.13 to 1.18 of the airfoil chord length.
TL;DR: In this paper, an Euler-Euler multiphase CFD model is proposed for continuous fast pyrolysis of biomass in a fluidized-bed reactor, where variable particle porosity is used to account for the evolution of the particle's physical properties, and particle kinetic processes and their interactions with the reactive gas phase are modeled with a multi-fluid description derived from the kinetic theory of granular flows.
Abstract: In this work, an Euler–Euler multiphase CFD model is proposed for continuous fast pyrolysis of biomass in a fluidized-bed reactor. In the model, a lumped, multi-component, multi-stage kinetic model is applied to describe the pyrolysis of a biomass particle. Variable particle porosity is used to account for the evolution of the particle's physical properties. Biomass is modeled as a composite of three reference components: cellulose, hemicellulose, and lignin. Pyrolysis products are categorized into three groups: gas, tar vapor (bio-oil), and solid char. The particle kinetic processes and their interactions with the reactive gas phase are modeled with a multi-fluid description derived from the kinetic theory of granular flows. A time-splitting approach is applied to decouple the convection and reaction calculations using a synchronized time step. The CFD model is employed to study the fast pyrolysis of both cellulose and bagasse in a lab-scale fluidized-bed reactor. The dynamics, particle heating, reaction of the biomass phase, char formation, elutriation, and spatial distribution of tar and gas inside the reactor are investigated. The yields of tar, gas, and char are also discussed.
TL;DR: In this article, the effect of orientation of the cantilever beam with tip mass on the efficiency of the power generated is experimentally studied, and a prototype is developed and attached onto the leg of a person walking on a treadmill at a constant speed.
Abstract: Harvesting energy from human body motion for powering small scale electronic devices is attracting research interest in recent years. Piezoelectric energy harvester (PEH) capable of harvesting energy from vibratory movement is a suitable candidate for this particular application. In this study, a cantilever beam with a piezoelectric patch attached at the end of the cantilever is evaluated for potential to harvest energy from human motion. Since the frequency of human walking motion is low, the frequency up conversion technique is adopted in this study to harvest the inertial energy. The effect of orientation of the cantilever beam with tip mass on the efficiency of the power generated is experimentally studied. A prototype is developed and attached onto the leg of a person walking on a treadmill at a constant speed. A theoretical lumped model is adopted to predict the voltage output using the experimentally measured acceleration as input data. Results show close agreement between the experiment and the model. Results also indicate that by varying the orientation of the PEH, the efficiency of the energy harvester can be significantly increased. Maximum power is found to be achieved when the PEH is orientated at 70° with reference to a coordinate system attached to the leg when walking on a treadmill.
TL;DR: LPG cookstoves met guidelines for Tier 4 for both CO and PM2.5 emissions and mostly met the World Health Organization Emission Rate Targets set to protect human health.
Abstract: Liquefied petroleum gas (LPG) cookstoves are considered to be an important solution for mitigating household air pollution; however, their performance has rarely been evaluated. To fill the data and knowledge gaps in this important area, 89 laboratory tests were conducted to quantify efficiencies and pollutant emissions from five commercially available household LPG stoves under different burning conditions. The mean thermal efficiency (±standard deviation) for the tested LPG cookstoves was 51 ± 6%, meeting guidelines for the highest tier level (Tier 4) under the International Organization for Standardization, International Workshop Agreement 11. Emission factors of CO2, CO, THC, CH4, and NOx on the basis of useful energy delivered (MJd) were 142 ± 17, 0.77 ± 0.55, 130 ± 196, 5.6 ± 8.2, and 46 ± 9 mg/MJd, respectively. Approximately 90% of the PM2.5 data were below the detection limit, corresponding to an emission rate below 0.11 mg/min. For those data above the detection limit, the average emission facto...
TL;DR: In this article , a review of key factors affecting the hydrogen production yield from steam gasification of plant-originated lignocellulosic biomass, including the design of the gasifier, temperature, pressure, and steam-to-biomass ratio, steam flow rate, moisture and particle size of fed biomass, and catalysts were thoroughly analyzed.
Abstract: Demands for the decline of CO2 emissions resulted in a significant transformation of the energy systems working on carbon sources towards more sustainable, clean, and renewable characteristics. Hydrogen is emerging as a secondary energy vector with ever-increasing importance in the decarbonisation progress. Indeed, hydrogen, a green and renewable energy source, could be produced from steam gasification of plant-originated lignocellulosic biomass. In this current review, key factors affect the hydrogen production yield from steam gasification of plant-originated lignocellulosic biomass, including the design of the gasifier, temperature, pressure, and steam-to-biomass ratio, steam flow rate, moisture and particle size of fed biomass, and catalysts were thoroughly analysed. Moreover, the effects of the abovementioned factors on the reduction of tar formation, which is also a key parameter towards ensuring the trouble-free operation of the reactor, were critically evaluated. More importantly, the separation of produced hydrogen from steam gasification of biomass and challenges over technological, environmental, and economic aspects of biomass gasification were also presented in detail. In addition, this paper is also profiling the prospect of Vietnam in fulfilling its hydrogen economy potential because Vietnam has vast biomass due to its tropical weather and availability of arable land, providing abundant lignocellulosic biomass with 45% of agricultural waste, 30% of firewood, and 25% of other sources. Besides, some primary factors hindering the broad application of biomass for hydrogen production were indicated. Finally, some solutions for implementing the hydrogenization strategy in Vietnam have also been discussed.
TL;DR: In this article, the stagnation point flow of radiative micropolar nanofluid over an off centered rotating disk with applications of motile microorganisms is reported. And the appropriate transformations are utilized to reduce the partial differential equations into dimensionless forms.
Abstract: To improve the heat efficiency base fluids (water, engine oil, glycol), the interaction of nanoparticles (nanotubes, droplets, nanowires, metals and non-metals) into such traditional liquids is the most frequent mechanism and attained the researchers attention, especially in current decade. The nanofluid is a suspension of submerged solid particles in base fluids. The nano-materials convinced the applications in the field of nanotechnology, thermal engineering, industrial and bio-engineering. Following to such motivating applications in mind, current research reports the stagnation point flow of radiative micropolar nanofluid over an off centered rotating disk with applications of motile microorganisms. The novel dynamic of thermal radiation and activation energy are also incorporated. The appropriate transformations are utilized to reduce the partial differential equations into dimensionless forms. A numerical shooting scheme is used to obtain the approximate solution with MATLAB software. The effects of prominent parameter on velocity profile, nanofluid temperature, concentration of nanoparticles and microorganism profile are physically incorporated.