M H Onsa

University of Khartoum, Mechanical Engineering, Faculty Member

Followers

138

Following

Co-author

Public Views

Associate Professor,B.Sc.(Mechanical Engineering), M.Sc.,PhD.
Phone: 00249922776759
Address: Khartoum, Al Khartum, Sudan

less

Abdo Adil

Ondokuz Mayıs Üniversitesi

Taha A L F A D U L Taha Ali

Alzaiem AlAzhari University

Shafiqur Rehman

King Fahd University of Petroleum and Minerals

Abdul Hadi N Khalifa

Middle East Technical University

Marie-Christine Record

Aix-Marseille University

Hebut

Technical University of Denmark (DTU)

MUSADAG EL ZEIN

InterestsView All (14)

Uploads

Papers by M H Onsa

Engineering-Economic Evaluation of Al-Fashir 5 MWp Mini-Grid Connected Photovoltaic Power Plant

Sudan's power sector is subject to frequent power discontinuity due fiscal and engineering proble... more Sudan's power sector is subject to frequent power discontinuity due fiscal and engineering problems. The Sudan has high solar irradiation eventuality, which is a radical solution to the problem of lack of electricity supply. Mini-grid system solar networks are a wise solution for such a wide country. This paper evaluates the Sudan first large solar photovoltaic (PV) operation (5 MWp) at Al-Fashir, in terms of power, cost, saving, responsibility and dependability. The project commissioned in 2020 for $6.8 M (turnkey price) and since then it is ready to supply a town to assist the 12 MW diesel power stations. The diurnal energy production is 31-28 MWh, this saves 7 tons of the gas-oil normally used by the diesel power plant. For a normal cost of the 1-Ton gas-oil of $600, the station will have a payback period of 3.2 years. From Al-Fashir mini-grid analysis, the five analogous power plants could be erected to assist the diesel plants partially for the daytime base load.

Download

Elastohydrodynamic lubrication study of hard rolling contact using boundary element method

Industrial Lubrication and Tribology, 2001

Presents a study on the application of boundary element method (BEM) to the solution of elastohyd... more Presents a study on the application of boundary element method (BEM) to the solution of elastohydrodynamic lubricated hard rolling contacts in comparison with a solution using finite difference method (FDM). The developed program for the solution of Reynolds equation and the elasticity equation give results of pressure distribution and the lubricant film thickness for steady state, isothermal Newtonian lubricant behavior. Compares the BEM results and the computer effort with the solution using FDM. Uses an iterative Newton‐Raphson method to solve the non‐linearity of the problem. Discusses the effects of Hertzian pressure and rolling speeds on film thickness and pressure distribution. The numerical scheme of BEM has proved to have the advantage of being very effective and optimum in terms of accuracy, less computational effort and good constancy compared to other applied numerical techniques.

Download

Development of an Empirical Coefficient for the Short Circuit Current to Determine Soiling Effect on PV Performance

University of Khartoum Engineering Journal, 2017

In this study, the effect of dust accumulation on the performance of photovoltaic (PV) module has... more In this study, the effect of dust accumulation on the performance of photovoltaic (PV) module has been shown. A statistical analysis has been conducted on a medium sized sample data collected from 30 hours of experimental work to obtain an empirical coefficient like temperature coefficients of short circuit current and open circuit voltage usually provided by manufacturers. This coefficient will be named dust coefficient of short circuit current and it will represent a predefined range of environmental conditions and soiling amounts; as the available testing conditions, and the statistical model prediction limits bound the coefficient extent of applicability.

Characterization of Photovoltaic Modules under Arid Environments

Journal of Energy and Power Engineering, 2018

Download

A Computer Procedure for Gas-Turbine Power Augmentation by Fog-Cooling

This paper describes a procedure for evaluating the gains from increased power and reduced heat r... more This paper describes a procedure for evaluating the gains from increased power and reduced heat rate of a gas turbine that result from pre-cooling the turbine's inlet-air by fogging. Unlike conventional media-type evaporative cooling, fogging can achieve 100% saturation of the air so that its temperature can be reduced to the wet-bulb temperature. The present procedure consists of two main sub-models; (i) an inlet-air evaporative cooling sub-model and (ii) a gas-turbine performance sub-model. The inlet-air cooling sub-model applies thermodynamic principles to determine the cooled air temperature prior to the compressor. The gas-turbine performance sub-model estimates, from the turbine's characteristic curves, the resulting improvements in the turbine's power and heat-rate and gives the expected hourly revenues. For the user's convenience, the procedure has been computer-programmed using MATLAB. The paper verifies the procedure against relevant published data before s...

Energy Strategies for Sustainable Development: The Malaysian Experience

ABSTRACT

The Influence of Al2O3- ZnO-H2O Nanofluid on the Thermodynamic Performance of Photovoltaic- Thermal Hybrid Solar Collector System

Innovative Energy & Research

A thermodynamic analysis was conducted after alternatively testing different working fluids to pa... more A thermodynamic analysis was conducted after alternatively testing different working fluids to particularly assess the effect of Nanofluid as heat transfer agent on improving thermal, electrical, and exergetic efficiencies of photovoltaic/thermal (PV/T) hybrid solar collector system under State of Qatar climate, using experimentally and computationally obtained data. The investigated fluids were water, and Al 2 O 3-ZnO-H 2 O Nanofluid mixed with Ethylene Glycol as surfactant. Mass fractions of Nanoparticles were 0.05 wt.% Al 2 O 3 with particle size of 5nm and 0.05 wt.% ZnO with particles size of 10-30 nm. The results showed that in comparison between water as absorption medium and the mentioned Nanofluid, an increase in thermal and hence total efficiency of the system was recorded for the latter absorption medium scenario, despite considering concentrations of the Nanoparticles relatively low. A very general trend of dramatic decrease in the positive effect of Nanofluid in consistency with the ambient temperature increase was also observed after fitting the data to segments of declining straight lines. For 0.05 wt.% mass fraction of Nanoparticles the averaged increment in total efficiency was 4.1%, and in total useable energy (exergy) efficiency was 4.6%.

Download

The Influence of Al 2 O 3 -ZnO-H 2 O Nanofluid on the Thermodynamic Performance of Photovoltaic-Thermal Hybrid Solar Collector System

Innovative Energy and Research, 2018

Download

Development of an Empirical Coefficient for the Short Circuit Current to Determine Soiling Effect on PV Performance

University of Khartoum Engineering Journal, 2017

Paper 3 MANAGEMENT OF EVAPORATION LOSSES OF GASOLINE'S

Elastohydrodynamic lubrication study of hard rolling contact using boundary element method

Economic measures of power plants

2017 International Conference on Communication, Control, Computing and Electronics Engineering (ICCCCEE), 2017

The objective of this paper is to provide financial analysis of both conventional and renewable r... more The objective of this paper is to provide financial analysis of both conventional and renewable resources power plants in order to assess the viability of projects and make an investment decision for the purpose of selecting the most viable one. An estimated scheme of utility-scale solar Photovoltaic system with 93.2 MW targeted designed capacity located around Khartoum area has been selected to be analyzed as a renewable resource power plant, on the other hand; Block 1 of Garri Power Station with the same rated power has been also selected as a conventional power plant, and a fair assessment has been achieved for both systems. The financial analysis is carried out using cash flow models in Excel work sheets, and the key economic measures used for the economic assessment process of include levelized cost of energy (LCOE), net present worth (NPW), internal rate of return (IRR), benefit-to-cost ratio (B/C) and payback period (PBP). The results gained from financial assessment show that the profitability of the utility-scale On-grid PV system is great comparing with that is of the combined cycle gas turbine power plant.

A brief summary of cleaning operations and their effect on the photovoltaic performance in Africa and the Middle East

Energy Reports

This article lists the technologies used to clean photovoltaic (PV) panels installed in Africa an... more This article lists the technologies used to clean photovoltaic (PV) panels installed in Africa and the Middle East. The peculiarity of the two regions is rooted in their sharing of the high capacity of the solar energy resource, the similarity in the dusty climates, and the intensive research conducted regarding dust soiling and mitigation. This concise summary contains an appraisal of the cleaning methods by naming their merits and drawbacks. The summary also tackles the optimization of the module tilt angle, which some researchers have shown interest in to enhance the gravitational forces that would reduce dust accumulation on PV surfaces. In the end, we included the cleaning frequencies that researchers recommended for several locations and concisely addressed the cleaning economics. We have drawn from this effort as a whole: First, we confirmed that the local climate contributes the most in selecting the cleaning method. Second, we can affirmatively claim that anti-soiling coatings are favored in North Africa, while water-based methods are popular in the gulf cooperation council countries. Third, natural cleaning by wind is ineffective in the desert regions of Africa and the Middle East. Last, the ideal cleaning frequency for Arabia is once a week and varies across Africa.

Evaluation of Safety Measures Inside Sudanese Thermal Power Plants

This paper is concerned with the evaluation of safety measures inside three electrical thermal po... more This paper is concerned with the evaluation of safety measures inside three electrical thermal power plants in Sudan. It also presents valuable information about areas of power plants, at which safety is strengthened, and areas of weakness and where, more corrective safety actions are required to enhance safety. The paper also has focused on the occupational health of employees inside power plants and, how can power plants employees, be trained to be ever safety cautious. The tools used in study included: questionnaires, field Inspection, noise level measurement and interviews with key employees in these plants. The evaluation results indicated that the overall safety performance index – which is estimated to be 0.56 –is below the recommended safety index, and that safety inside thermal power plants in Sudan is an issue of a great concern. This requires the attention and direct intervention of higher authorities to take

Download

Investigation on the Problems of Handpumps in Sudan Investigation on the Problems of Handpumps in Sudan

Elastohydrodynamic Analysis of Rolling Line Contact Using Boundary Element Method

This study aims at incorporating the use of the boundary element method (BEM) as an efficient and... more This study aims at incorporating the use of the boundary element method (BEM) as an efficient and fast numerical method for the solution of the problem of the elastohydrodynamic (EHL) of hard rolling line contact. EHL of hard rolling is the dominant mode of lubrication in many critical, highly stressed machine elements such as gears, cams and followers, and bearings. The study of the stress concentration and deformation is important to predict the performance and the life expectancy against failures. These failures are manifested in wear, fatigue and scuffing. This fundamental study is based on isothermal, steady state, and smooth line contact EHL. The rolling of two cylindrical rollers was approximated by a roller and a plane. The hard rolling EHL relates to counter-formal contact elements made of high elastic modulus materials such as metals. The problem is to seek a solution, which reconciles the hydrodynamic equation represented by the Reynolds equation, and the elasticity equation while at the same time allowing for the variation of the lubricant properties with pressure. The resultant regime is highly non-linear. A hybrid solution is util ised to solve the elasticity problem using the BEM, and to solve the Reynolds equation for the pressure us ing the finite difference method (FDM) in a ful ly coupled solution. The BEM fundamental ly consists of the transformation of the partial differential equations, which describe the behaviour of the variables ins ide and on the boundary of the domain into integral equation relating to the boundary values, and the numerical solution of these equations. The boundary integral equation is formulated for the elasticity and solved using the BEM. The hydrodynam ic equation is solved using FDM. The coupled solution i s solved using Newton-Raphson iterative technique. The converged solut ion gives the pressure distibution and the l ubricant film thickness. The overa l l result of executi ng the hybrid BEM-FDM program gives a ful l agreement when compared to the program using FDM while resu lting i n reduction in the C PU time. The results also agree with other published numerical works. These veri fy the use of the developed method. To fu l ly uti l ize the advancement of the developed program, an extension of the models needs to include a non-Newtonian behaviour of l ubricant and the thermal effects.

Paper 2 Energy Strategies for Sustainable Development

Management of Evaporation Losses of Gasoline's Storage Tanks

Gasoline is a volatile organic compound (VOCs) which consists of different hydrocarbons with diff... more Gasoline is a volatile organic compound (VOCs) which consists of different hydrocarbons with different boiling points in the range of 30-200 o C. The light compounds that have boiling point of less than 40 o C constitute about 10%. Khartoum, Sudan is characterized with an average of 10 hrs of sunshine and solar radiation of 3.05-7.62 kWh/m 2 /day and average temperature of 32 to 40 o C. Under these conditions high evaporation rate is expected from storage tanks. The objective of this study is to evaluate the evaporation loss of gasoline from internal floating roof storage tank. The case study is based on metrological and operation data for the year 2008. The result revealed that the total evaporation loss is 0.5%. This is significantly higher than that set by the ministry of energy [i.e.0.25%]. The results should be of concern to the petroleum industries and government. The reduction of evaporation loss of gasoline will give attractive economic returns as well as reducing air pollut...

Potential Sites for Hydropower Generation at Khor Langeib

This paper aims to present feasible potential sites at Khor Langeib which are suitable for hydrop... more This paper aims to present feasible potential sites at Khor Langeib which are suitable for hydropower generation. Khor Langeib, in Kassala State – Sudan, is part of the proposed route for supplying Port-Sudan and the Red Sea coastal plain with water from River Atbara. Water is expected to drop 260m along 142km in the Khor. From studying suitable nine sites at the Khor, the best seven sites were sele cted and preliminarily checked for suitability to hydropower generation applying criteria of: facilitating enough head of 16m to 63m, suitable topography and optimum volume of dam structure. Two other alternative scenarios are tested: First scenario of usi ng three dams; and the second scenario adopted 8 dams. The two alternative scenarios revealed increase in dams' average volume0 compared with the selected. dams0 by 162% and 62%, respectively. Based on availability of materials, rock-fill gravity dams are suggested with impermeable core of roller compacted concrete (RCC) or membran...