Kamal Abed - Profile on Academia.edu (original) (raw)
Papers by Kamal Abed
A semi-industrial reactor for producing biodiesel from waste cooking oil
Biofuels
The effect of battery characteristics on the performance of PV Energy System is experimentally in... more The effect of battery characteristics on the performance of PV Energy System is experimentally investigated. The employed system consists of a number of lead acid storage batteries, a set of photovoltaic (PV) panels, a charge controller, DC/AC inverter and an electrical load. The system also employs a monitoring unit (MU) that consists of voltage and current sensors and data acquisition cards. The MU was specially developed to monitor energy system performance parameters; such as PV voltage and current, battery voltage, battery charging and discharging currents and inverter current. The monitoring unit is controlled through a specially developed, LABVIEW® based, computer program. In the study, the effect of battery SOC on charging and charging efficiency was investigated. Also, the effect of battery’s loading conditions on its useful charge was investigated. Finally, the effect of battery SOC and supported load on battery performance was investigated. Results of the study showed bat...
Experimental results of PV-diesel hybrid energy system
Generalized performance characteristics of turbine stage groups. An attempt to supplement the Flugel's-Stodola's law
Archive of Mechanical Engineering, 2000
Numerical investigations were carried out for flow fields of a flanged diffuser wind turbine. Inf... more Numerical investigations were carried out for flow fields of a flanged diffuser wind turbine. Influence of expansion angle, diffuser length, flange height and load factor on the flow field described by velocity contours, static pressure contours and streamlines was investigated. A commercial package “ANSYS FLUENT 14.5" is used as a solver, while Gambit program is used for constructing the problem domain and mesh generation. The results showed that increasing the expansion angle leads to accelerate the flow through the diffuser when the angles are between 0° and 12° where the flow field is characterized by undisturbed streamline flows, after that the expansion angle effect become negligible as the secondary fluid circulation is generated near the end of the diffuser and grow with expansion angle. Also increasing the diffuser length accelerates the flow entering the diffuser until the diffuser length to inlet diameter ratio reaches a value of 1.25. After that, a recirculation zon...
Microwave Post-Treatment of PES Hollow Fiber Membranes immersed in NaCl Solution
Polyethersulfone (PES) hollow fiber membranes (HFMs) are widely used in diverse fields such as bi... more Polyethersulfone (PES) hollow fiber membranes (HFMs) are widely used in diverse fields such as biomedical and numerous water treatment applications as ultrafiltration (UF) and nanofiltraton (NF). Tuning of surface morphology and mechanical characteristics is essential for successful performance, which is related to the target application. In this paper, microwave (MW) irradiation has been utilized as a post-treatment technique for the tuning of the above mentioned characteristics. Investigations are centered on variation of the saline bath containing different concentrations of sodium chloride (NaCl) (1-4 wt%) as an external heat transfer medium at a specific temperature and duration. The MW irradiated HFMs have been characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and numerous mechanical testing parameters. Investigations in the above mentioned range indicates that at 2% sodium chloride solution concentration unique properties prevailed, where it s...
The present work aims to manage the thermal energy stored from concentrated solar power (CSP) res... more The present work aims to manage the thermal energy stored from concentrated solar power (CSP) research plant, in order to obtain the best operating condition of CSP system. This plant consists of solar collector field of 120 kW peak thermal capacity, thermal storage tank with 3 tons of therminol-66 oil, an organic rankine cycle (ORC) of 8 kW nominal electric power production capacity, and thermally driven absorption chiller (TDC) of 35 kW cooling capacity. The system was modeled mathematically then calculated using engineering equation solver (EES) software in order to analyze the performance at similar conditions to the real ones to ensure the feasibility of the presented study. When increasing the input thermal power for both ORC and TDC, the kWh cost decreases. The lowest price for ORC kWh is 1.131 /kWhwhen100/kWh when 100% of the stored thermal power is used by ORC to generate electricity. Also, the lowest price for TDC kWh is 0.1214 /kWhwhen100/kWh when 100% of the stored thermal power is directed...
ERJ. Engineering Research Journal, 2009
In this paper, the effect of integration cap size on geoid determination was studied, when using ... more In this paper, the effect of integration cap size on geoid determination was studied, when using gravity disturbances and vertical deflection as input data. For this purpose, a series of varying cap radii was used to predict gravimetric geoidal heights at discrete GPS-Benchmarks, using both the Hotine and deflection-geoid techniques. In both cases, the results showed significant dependence of the resulting geoid accuracy on the integration cap size. The two methods showed comparable behavior in the vicinity of the cap radius, which i s consistent wit? the maximal resolution of the reference geopotential model. At larger cap sizes, the perfomance of the deflection data type was significantly better than the gravity disturbances, which in turn showed a dramatic degradation of the geoid accuracy. Therefore, when solving for the geoid without modifying the integration kemel, it is strongly recommended to nse large cap sizes along with the deflection-geoid method. If gravity disturbances are to be used for geoid determination, then it is recommended to use as small integration cap as possible.
Applied Thermal Engineering, 2018
This study aims at computing the optimum conditions for a counter flow cooling tower such that th... more This study aims at computing the optimum conditions for a counter flow cooling tower such that the operating cost is minimized. Consequently, an optimization model is employed and validated to be used in further studies The unit prices for water and electricity were taken for industrial applications in Egypt. A 4-ODE model describing the mass and heat transfer within a counter flow cooling tower is solved numerically employing the shooting method. The model is solved under the MATLAB platform. Particle swarm optimization algorithm is successfully implemented for the optimization problem. The results show that at heat load corresponding to 940.5kW, the minimum operating cost corresponded to 15.7% increase when the area of the fill was increased from 5.5m 2 to 8.5m 2. The operating cost due to make-up water compromised the majority of the operating cost. The percentage decrease in the operating cost corresponded to 17.2% and 5.6% for an increase of 0.3m in length (0.6-0.9m) and (0.9-1.2m) respectively.
Fullerenes, Nanotubes and Carbon Nanostructures, 2017
The effect of graphene nanosheets (GNS) on the rheological characteristics and thermal conductivi... more The effect of graphene nanosheets (GNS) on the rheological characteristics and thermal conductivity of calcium grease used in marine applications, and water pumps for lower demanding applications, has been experimentally evaluated in this paper. Various volume fractions of GNS (0.5, 1, 2, 3, and 4% wt.) have been immersed in the grease aiming at finding the better percentages that improve the properties of nanogrease. The rheological characteristics and thermal conductivity were evaluated with a Brookfield Rheometer DV-III ULTRA and KD2 thermal analyzer, respectively. The results of the modified calcium grease indicated that the best concentration of GNS is 3% wt. The rheological characteristics of the grease with a different volume fraction of GNS indicated a non-Newtonian behavior. Thermal conductivity of nanogreas also increases with an increase of GNS volume fraction. Moreover, the apparent viscosity, shear stress and dropping point increase by 59%, 52%, and 65%, respectively, with increasing GNS volume fraction.
Tribological behaviour of calcium grease containing carbon nanotubes additives
Industrial Lubrication and Tribology, 2016
Purpose The purpose of this paper is to fabricate composite nanogrease for tribological applicati... more Purpose The purpose of this paper is to fabricate composite nanogrease for tribological applications. Multi-walled carbon nanotubes (MWCNTs) with a size 10 nm average diameter and 5 μm in length were used as additives to calcium grease. Design/methodology/approach The tribological four-ball machine was used to evaluate calcium grease with carbon nanotubes (CNTs) as an additive. The interaction between CNT and calcium grease (nanogrease) were studied by transmission electron microscopy and X-ray diffraction. Findings MWCNTs composite nanogrease was manufactured for tribological applications. The effectiveness of the fabricated grease in improving the tribological performance at different concentrations and under different loads was tested. The results are summarized as follows. CNT nanoparticle additive dispersed in calcium grease significantly improve its anti-wear performance, reducing friction, increasing load-carrying capacity and extreme pressure (EP) property. The friction is r...
Journal of Dispersion Science and Technology, 2016
The addition of graphene nanosheets in lubricating grease could significantly reduce the interfac... more The addition of graphene nanosheets in lubricating grease could significantly reduce the interfacial friction and improve the load-bearing capacity of the parts. Therefore it has been considered as having great potential as lubricant additives. In this study, we synthesis graphene nanosheets (GNS) which are prepared by a modified Hummer method, and investigated the effect of GNS with different concentration (0.5%, 1%, 2%, 3%, and 4%wt.) on the tribological properties of the calcium grease. The friction and wear experiments were performed using a four ball tribometer. Transmission Electron Microscopy (TEM) and Scanning electron microscopy (SEM) were employed to examine the GNS and the friction mechanisms. Results indicate that the friction reduction ability and anti-wear property of the base grease can be improved with the addition of GNS. It was also found that the friction reduction decrease by 61 %, and the wear scar diameter (WSD) decreases by 45 %, and the extreme pressure (EP) properties increased 60 % at 3% wt GNS. It's clearly; the GNS in grease easily form protective deposited films to prevent the rubbing surfaces from coming into direct contact and, thereby, improve the entire tribological behavior of the grease.
Rheology and Thermal Conductivity of Calcium Grease Containing Multi-Walled Carbon Nanotube
Fullerenes, Nanotubes and Carbon Nanostructures, 2016
ABSTRACT Recently, nanofluids attract considerable interest for enhanced rheological behavior and... more ABSTRACT Recently, nanofluids attract considerable interest for enhanced rheological behavior and thermal performance. The aim of this research is to study the influence of additives Multi-Walled Carbon Nanotubes (MWCNTs) on the rheological behavior and its structure, thermal conductivity, and the influence of shear thinning rate on oil separation at different temperatures for calcium grease. Various concentrations of MWCNTs (0.5, 1, 2, 3, and 4%) have been added to the grease to obtain the best percentages that improve the properties of nanofluid. The microstructure of MWCNTs and nanofluid were examined by X-ray diffraction (XRD), Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM). These experimental investigations were evaluated with a Brookfield programmable Rheometer DV-III ULTRA. The results indicated that the optimum concentration of MWCNTs was 3%, and the dropping point increasing about 11%. The rheological behaviors of the nanofluids show that the grease with various concentrations of MWCNTs demonstrates non Newtonian behaviors and the results indicated that the shear stress, apparent viscosity and thermal conductivity increase with the increase of volume concentration of MWCNTs to 65%, 52%, and% 56, respectively.
In this work, a single zone compression ignition engine cycle model is used to predict the cycle ... more In this work, a single zone compression ignition engine cycle model is used to predict the cycle performance of a diesel engine for the cases of using diesel fuel blends of 20, 40, 70, 100 %, unheated jatropha oil (J100) and preheated jatropha oil at a temperature of 90°C (PHJ90). The apparent fuel burning rate could be expressed as the sum of two components, one relating to premixed and the other to diffusion burning. A computer code for the cycle model has been prepared by MATLAB to perform numerical calculations. The effect of load variation on peak cylinder pressure, specific fuel consumption and thermal efficiency is analyzed. An experimental investigation has been carried out on a diesel engine fuelled with B20, B100, PHJ90, J100 and diesel fuels.
Performance of a wind-turbine-driven compressor for lifting water
Energy, 1997
... Wind turbine According to bladeelement theory, the output power from a wind turbine is P ... ... more ... Wind turbine According to bladeelement theory, the output power from a wind turbine is P ... A mathematical model and a computer program which simulate the operation of a smallscale wind turbine has been constructed by Abed et al.5 The computer program was loaded ...
Energy, 1997
Offshore wind energy technology has developed rapidly over the last decade. It is expected to sig... more Offshore wind energy technology has developed rapidly over the last decade. It is expected to significantly contribute to the further increase of renewable energy in the global energy production in the future. However, even with floating wind turbines, only a fraction of the global offshore wind energy potential can be harvested because grid-connection, moorings, installation and maintenance costs increase tremendously as the distance to shore and the water depth increase. Thus, new technologies enabling harvesting the far offshore wind energy resource are required. To tackle this challenge, mobile energy ship concepts have been proposed. In those concepts, electricity is produced by a water turbine attached underneath the hull of a ship propelled by the wind using sails. It includes an on-board energy storage system since energy ships are not grid-connected. Thus, the ships route schedules could be dynamically optimized taking into account weather forecast in order to maximize their capacity factors (CF). The aim of this study is to investigate how high the capacity factors of energy ships could be when using weather-routing and compare them to that of stationary wind turbines that would be deployed in the same areas. To that end, a modified version of the weather-routing software QtVlm was used. Velocity and power production polar plots of an energy ship that was designed at LHEEA were used as input to QtVlm. Results show that capacity factors over 80% can be achieved with energy ships and stationary offshore wind turbines deployed in the North Atlantic Ocean.
There is heavy dependence on fossil fuels for energy production. These are not only depletable bu... more There is heavy dependence on fossil fuels for energy production. These are not only depletable but also are the main cause of emissions and global warming. Renewable energy and biofuels can play significant role in this concern. This research is concerned with the efficient production of biodiesel from Jatropha seeds. We designed and operated an efficient screw press for continuous production of biodiesel. The effects of many parameters which affect the oil yield from the press were studied in order to determine the optimum operating conditions for maximum yield. The objective of this paper is to obtain the optimum speed and preheating temperature of our screw press to get improved properties of extraction oil, minimum extraction time and minimum motor power. The present screw press is specially designed on laboratory scale. The influence of different motors speeds of 20, 60, 100 and 140 rpm and preheating temperatures 50, 75, 100 and 125 °C on oil extraction yield were investigated...
Egyptian Journal of Chemistry
Fossil fuel consumption and harmful emissions increase led to intensive search for alternative fu... more Fossil fuel consumption and harmful emissions increase led to intensive search for alternative fuels. The present oil was extracted from Egyptian jatropha nuts by using a designed and manufactured screw press at a preheating temperature of 100°C and operational screw speed of 60 rpm. Esterification followed by transesterification produced biodiesel from jatropha oil. Heat recovery from exhaust gases at a temperature of 90°C was utilized to preheat the produced jatropha oil. Jatropha biodiesel was preheated to a temperature of 40°C. Measured properties of preheated biodiesel and jatropha oil were found to be within ASTM standards. The present research studied the performance and emissions of a diesel engine burning preheated biodiesel and bio oil compared to diesel fuel. Experimental tests were carried out from zero to full load. The results revealed that about 2% decrease in the brake specific fuel consumption and 2% increase in the brake thermal efficiency for preheated jatropha oi...
A semi-industrial reactor for producing biodiesel from waste cooking oil
Biofuels
The effect of battery characteristics on the performance of PV Energy System is experimentally in... more The effect of battery characteristics on the performance of PV Energy System is experimentally investigated. The employed system consists of a number of lead acid storage batteries, a set of photovoltaic (PV) panels, a charge controller, DC/AC inverter and an electrical load. The system also employs a monitoring unit (MU) that consists of voltage and current sensors and data acquisition cards. The MU was specially developed to monitor energy system performance parameters; such as PV voltage and current, battery voltage, battery charging and discharging currents and inverter current. The monitoring unit is controlled through a specially developed, LABVIEW® based, computer program. In the study, the effect of battery SOC on charging and charging efficiency was investigated. Also, the effect of battery’s loading conditions on its useful charge was investigated. Finally, the effect of battery SOC and supported load on battery performance was investigated. Results of the study showed bat...
Experimental results of PV-diesel hybrid energy system
Generalized performance characteristics of turbine stage groups. An attempt to supplement the Flugel's-Stodola's law
Archive of Mechanical Engineering, 2000
Numerical investigations were carried out for flow fields of a flanged diffuser wind turbine. Inf... more Numerical investigations were carried out for flow fields of a flanged diffuser wind turbine. Influence of expansion angle, diffuser length, flange height and load factor on the flow field described by velocity contours, static pressure contours and streamlines was investigated. A commercial package “ANSYS FLUENT 14.5" is used as a solver, while Gambit program is used for constructing the problem domain and mesh generation. The results showed that increasing the expansion angle leads to accelerate the flow through the diffuser when the angles are between 0° and 12° where the flow field is characterized by undisturbed streamline flows, after that the expansion angle effect become negligible as the secondary fluid circulation is generated near the end of the diffuser and grow with expansion angle. Also increasing the diffuser length accelerates the flow entering the diffuser until the diffuser length to inlet diameter ratio reaches a value of 1.25. After that, a recirculation zon...
Microwave Post-Treatment of PES Hollow Fiber Membranes immersed in NaCl Solution
Polyethersulfone (PES) hollow fiber membranes (HFMs) are widely used in diverse fields such as bi... more Polyethersulfone (PES) hollow fiber membranes (HFMs) are widely used in diverse fields such as biomedical and numerous water treatment applications as ultrafiltration (UF) and nanofiltraton (NF). Tuning of surface morphology and mechanical characteristics is essential for successful performance, which is related to the target application. In this paper, microwave (MW) irradiation has been utilized as a post-treatment technique for the tuning of the above mentioned characteristics. Investigations are centered on variation of the saline bath containing different concentrations of sodium chloride (NaCl) (1-4 wt%) as an external heat transfer medium at a specific temperature and duration. The MW irradiated HFMs have been characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and numerous mechanical testing parameters. Investigations in the above mentioned range indicates that at 2% sodium chloride solution concentration unique properties prevailed, where it s...
The present work aims to manage the thermal energy stored from concentrated solar power (CSP) res... more The present work aims to manage the thermal energy stored from concentrated solar power (CSP) research plant, in order to obtain the best operating condition of CSP system. This plant consists of solar collector field of 120 kW peak thermal capacity, thermal storage tank with 3 tons of therminol-66 oil, an organic rankine cycle (ORC) of 8 kW nominal electric power production capacity, and thermally driven absorption chiller (TDC) of 35 kW cooling capacity. The system was modeled mathematically then calculated using engineering equation solver (EES) software in order to analyze the performance at similar conditions to the real ones to ensure the feasibility of the presented study. When increasing the input thermal power for both ORC and TDC, the kWh cost decreases. The lowest price for ORC kWh is 1.131 /kWhwhen100/kWh when 100% of the stored thermal power is used by ORC to generate electricity. Also, the lowest price for TDC kWh is 0.1214 /kWhwhen100/kWh when 100% of the stored thermal power is directed...
ERJ. Engineering Research Journal, 2009
In this paper, the effect of integration cap size on geoid determination was studied, when using ... more In this paper, the effect of integration cap size on geoid determination was studied, when using gravity disturbances and vertical deflection as input data. For this purpose, a series of varying cap radii was used to predict gravimetric geoidal heights at discrete GPS-Benchmarks, using both the Hotine and deflection-geoid techniques. In both cases, the results showed significant dependence of the resulting geoid accuracy on the integration cap size. The two methods showed comparable behavior in the vicinity of the cap radius, which i s consistent wit? the maximal resolution of the reference geopotential model. At larger cap sizes, the perfomance of the deflection data type was significantly better than the gravity disturbances, which in turn showed a dramatic degradation of the geoid accuracy. Therefore, when solving for the geoid without modifying the integration kemel, it is strongly recommended to nse large cap sizes along with the deflection-geoid method. If gravity disturbances are to be used for geoid determination, then it is recommended to use as small integration cap as possible.
Applied Thermal Engineering, 2018
This study aims at computing the optimum conditions for a counter flow cooling tower such that th... more This study aims at computing the optimum conditions for a counter flow cooling tower such that the operating cost is minimized. Consequently, an optimization model is employed and validated to be used in further studies The unit prices for water and electricity were taken for industrial applications in Egypt. A 4-ODE model describing the mass and heat transfer within a counter flow cooling tower is solved numerically employing the shooting method. The model is solved under the MATLAB platform. Particle swarm optimization algorithm is successfully implemented for the optimization problem. The results show that at heat load corresponding to 940.5kW, the minimum operating cost corresponded to 15.7% increase when the area of the fill was increased from 5.5m 2 to 8.5m 2. The operating cost due to make-up water compromised the majority of the operating cost. The percentage decrease in the operating cost corresponded to 17.2% and 5.6% for an increase of 0.3m in length (0.6-0.9m) and (0.9-1.2m) respectively.
Fullerenes, Nanotubes and Carbon Nanostructures, 2017
The effect of graphene nanosheets (GNS) on the rheological characteristics and thermal conductivi... more The effect of graphene nanosheets (GNS) on the rheological characteristics and thermal conductivity of calcium grease used in marine applications, and water pumps for lower demanding applications, has been experimentally evaluated in this paper. Various volume fractions of GNS (0.5, 1, 2, 3, and 4% wt.) have been immersed in the grease aiming at finding the better percentages that improve the properties of nanogrease. The rheological characteristics and thermal conductivity were evaluated with a Brookfield Rheometer DV-III ULTRA and KD2 thermal analyzer, respectively. The results of the modified calcium grease indicated that the best concentration of GNS is 3% wt. The rheological characteristics of the grease with a different volume fraction of GNS indicated a non-Newtonian behavior. Thermal conductivity of nanogreas also increases with an increase of GNS volume fraction. Moreover, the apparent viscosity, shear stress and dropping point increase by 59%, 52%, and 65%, respectively, with increasing GNS volume fraction.
Tribological behaviour of calcium grease containing carbon nanotubes additives
Industrial Lubrication and Tribology, 2016
Purpose The purpose of this paper is to fabricate composite nanogrease for tribological applicati... more Purpose The purpose of this paper is to fabricate composite nanogrease for tribological applications. Multi-walled carbon nanotubes (MWCNTs) with a size 10 nm average diameter and 5 μm in length were used as additives to calcium grease. Design/methodology/approach The tribological four-ball machine was used to evaluate calcium grease with carbon nanotubes (CNTs) as an additive. The interaction between CNT and calcium grease (nanogrease) were studied by transmission electron microscopy and X-ray diffraction. Findings MWCNTs composite nanogrease was manufactured for tribological applications. The effectiveness of the fabricated grease in improving the tribological performance at different concentrations and under different loads was tested. The results are summarized as follows. CNT nanoparticle additive dispersed in calcium grease significantly improve its anti-wear performance, reducing friction, increasing load-carrying capacity and extreme pressure (EP) property. The friction is r...
Journal of Dispersion Science and Technology, 2016
The addition of graphene nanosheets in lubricating grease could significantly reduce the interfac... more The addition of graphene nanosheets in lubricating grease could significantly reduce the interfacial friction and improve the load-bearing capacity of the parts. Therefore it has been considered as having great potential as lubricant additives. In this study, we synthesis graphene nanosheets (GNS) which are prepared by a modified Hummer method, and investigated the effect of GNS with different concentration (0.5%, 1%, 2%, 3%, and 4%wt.) on the tribological properties of the calcium grease. The friction and wear experiments were performed using a four ball tribometer. Transmission Electron Microscopy (TEM) and Scanning electron microscopy (SEM) were employed to examine the GNS and the friction mechanisms. Results indicate that the friction reduction ability and anti-wear property of the base grease can be improved with the addition of GNS. It was also found that the friction reduction decrease by 61 %, and the wear scar diameter (WSD) decreases by 45 %, and the extreme pressure (EP) properties increased 60 % at 3% wt GNS. It's clearly; the GNS in grease easily form protective deposited films to prevent the rubbing surfaces from coming into direct contact and, thereby, improve the entire tribological behavior of the grease.
Rheology and Thermal Conductivity of Calcium Grease Containing Multi-Walled Carbon Nanotube
Fullerenes, Nanotubes and Carbon Nanostructures, 2016
ABSTRACT Recently, nanofluids attract considerable interest for enhanced rheological behavior and... more ABSTRACT Recently, nanofluids attract considerable interest for enhanced rheological behavior and thermal performance. The aim of this research is to study the influence of additives Multi-Walled Carbon Nanotubes (MWCNTs) on the rheological behavior and its structure, thermal conductivity, and the influence of shear thinning rate on oil separation at different temperatures for calcium grease. Various concentrations of MWCNTs (0.5, 1, 2, 3, and 4%) have been added to the grease to obtain the best percentages that improve the properties of nanofluid. The microstructure of MWCNTs and nanofluid were examined by X-ray diffraction (XRD), Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM). These experimental investigations were evaluated with a Brookfield programmable Rheometer DV-III ULTRA. The results indicated that the optimum concentration of MWCNTs was 3%, and the dropping point increasing about 11%. The rheological behaviors of the nanofluids show that the grease with various concentrations of MWCNTs demonstrates non Newtonian behaviors and the results indicated that the shear stress, apparent viscosity and thermal conductivity increase with the increase of volume concentration of MWCNTs to 65%, 52%, and% 56, respectively.
In this work, a single zone compression ignition engine cycle model is used to predict the cycle ... more In this work, a single zone compression ignition engine cycle model is used to predict the cycle performance of a diesel engine for the cases of using diesel fuel blends of 20, 40, 70, 100 %, unheated jatropha oil (J100) and preheated jatropha oil at a temperature of 90°C (PHJ90). The apparent fuel burning rate could be expressed as the sum of two components, one relating to premixed and the other to diffusion burning. A computer code for the cycle model has been prepared by MATLAB to perform numerical calculations. The effect of load variation on peak cylinder pressure, specific fuel consumption and thermal efficiency is analyzed. An experimental investigation has been carried out on a diesel engine fuelled with B20, B100, PHJ90, J100 and diesel fuels.
Performance of a wind-turbine-driven compressor for lifting water
Energy, 1997
... Wind turbine According to bladeelement theory, the output power from a wind turbine is P ... ... more ... Wind turbine According to bladeelement theory, the output power from a wind turbine is P ... A mathematical model and a computer program which simulate the operation of a smallscale wind turbine has been constructed by Abed et al.5 The computer program was loaded ...
Energy, 1997
Offshore wind energy technology has developed rapidly over the last decade. It is expected to sig... more Offshore wind energy technology has developed rapidly over the last decade. It is expected to significantly contribute to the further increase of renewable energy in the global energy production in the future. However, even with floating wind turbines, only a fraction of the global offshore wind energy potential can be harvested because grid-connection, moorings, installation and maintenance costs increase tremendously as the distance to shore and the water depth increase. Thus, new technologies enabling harvesting the far offshore wind energy resource are required. To tackle this challenge, mobile energy ship concepts have been proposed. In those concepts, electricity is produced by a water turbine attached underneath the hull of a ship propelled by the wind using sails. It includes an on-board energy storage system since energy ships are not grid-connected. Thus, the ships route schedules could be dynamically optimized taking into account weather forecast in order to maximize their capacity factors (CF). The aim of this study is to investigate how high the capacity factors of energy ships could be when using weather-routing and compare them to that of stationary wind turbines that would be deployed in the same areas. To that end, a modified version of the weather-routing software QtVlm was used. Velocity and power production polar plots of an energy ship that was designed at LHEEA were used as input to QtVlm. Results show that capacity factors over 80% can be achieved with energy ships and stationary offshore wind turbines deployed in the North Atlantic Ocean.
There is heavy dependence on fossil fuels for energy production. These are not only depletable bu... more There is heavy dependence on fossil fuels for energy production. These are not only depletable but also are the main cause of emissions and global warming. Renewable energy and biofuels can play significant role in this concern. This research is concerned with the efficient production of biodiesel from Jatropha seeds. We designed and operated an efficient screw press for continuous production of biodiesel. The effects of many parameters which affect the oil yield from the press were studied in order to determine the optimum operating conditions for maximum yield. The objective of this paper is to obtain the optimum speed and preheating temperature of our screw press to get improved properties of extraction oil, minimum extraction time and minimum motor power. The present screw press is specially designed on laboratory scale. The influence of different motors speeds of 20, 60, 100 and 140 rpm and preheating temperatures 50, 75, 100 and 125 °C on oil extraction yield were investigated...
Egyptian Journal of Chemistry
Fossil fuel consumption and harmful emissions increase led to intensive search for alternative fu... more Fossil fuel consumption and harmful emissions increase led to intensive search for alternative fuels. The present oil was extracted from Egyptian jatropha nuts by using a designed and manufactured screw press at a preheating temperature of 100°C and operational screw speed of 60 rpm. Esterification followed by transesterification produced biodiesel from jatropha oil. Heat recovery from exhaust gases at a temperature of 90°C was utilized to preheat the produced jatropha oil. Jatropha biodiesel was preheated to a temperature of 40°C. Measured properties of preheated biodiesel and jatropha oil were found to be within ASTM standards. The present research studied the performance and emissions of a diesel engine burning preheated biodiesel and bio oil compared to diesel fuel. Experimental tests were carried out from zero to full load. The results revealed that about 2% decrease in the brake specific fuel consumption and 2% increase in the brake thermal efficiency for preheated jatropha oi...