Hydrogen is one of the most promising options being considered as the fuel of future. However, injection of hydrogen into modern gasoline fueled engines can cause some issues such as power loss. This ...study, therefore, aims to address this challenge in a simulated hydrogen/gasoline dual-fueled engine by developing a novel and innovative approach without possible side effects such as NOx increment. To achieve this goal, the impacts of water injection and the start of the combustion (SOC) modification in a gasoline/hydrogen duel fueled engine have been rigorously investigated. In current methodology, an engine is simulated using AVL BOOST software and the model is validated against the experimental data. The Latin Hypercube design of experiments method was employed to determine the design points in 3-dimensional space. Due to the existing trade-off between NOx and BMEP, multi-objective optimization using genetic algorithm (GA) was implemented to determine the optimum values of water injection and SOC in various hydrogen energy shares and the effects of optimum design parameters on the main engine performance and emission parameters were investigated. The results showed that the proposed solution could recover the brake mean effective pressure (BMEP) and in some hydrogen energy shares even increase it above the level of single fueled gasoline engine with the added benefit of there being no increase in NOx compared to the original level. Furthermore, other emissions and engine performance parameters are improved including the engine equivalent Brake specific fuel consumption (BSFC) which was shown to increased up to 4.61%.
•Water injection and SOC modification improved hydrogen/gasoline engine performance.•BMEP was recovered by optimized SOC and water injection.•Engine BSFC was reduced up to 4.61%.•A significant NOx reduction of up to 59% was achieved.
•Developing and validating metamodels of heating and cooling energy needs.•Reducing drastically the number of simulations using design of experiment method.•Simultaneous optimization based ...desirability function and simplex algorithm.•Proposing technical solutions for minimizing the building energy needs in Morocco.•Proposing technical solutions for satisfying the thermal building code in Morocco.
The building sector is the largest consumer of energy in Morocco with a share of about 36% of the overall energy consumption of the country. This rate is likely to increase if the new buildings are energy consuming. In order to achieve a high energy performance of the building, an optimization of the building envelope is required. This study is often complex and time consuming due to the large number of parameters to consider. The aim of this research work is, on the one hand, to develop and validate metamodels of heating and cooling energy needs for single family houses in six Moroccan climate zones. These metamodels are obtained by regression approach from a set of dynamic simulations of the building behavior. The number of dynamic simulations is reduced drastically by using the design of experiments method. On the other hand, from the metamodels developed, a simultaneous optimization of the building envelope is performed based desirability function concept and the simplex Nelder–Mead algorithm. This methodology is used successfully to perform a fast operational optimization of building envelopes to enhance the implementation of low energy buildings in Morocco.
•A thermal solar system for space heating was designed and built.•A TRNSYS model is developed and validated through experimental measurement.•A sensitivity approach is proposed to quantify the ...influence of the design parameters on solar fraction.•Pump control impacts considerably the solar fraction in large solar systems.•The proposed approach can be used for the optimization of solar space heating systems design.
In this paper, a solar water heating system (SWHS) based on 4 m2 flat plate collectors is integrated to an office building to ensure the heat demand. The SWHS is equipped with Labview software and a multichannel digital card that makes the system control and data acquisition automatic. A TRNSYS model is developed and validated against experimental data and then used for optimization purposes. A sensitivity approach based on the Design of Experiments method and dynamic simulations is proposed to optimize the solar fraction. For this purpose, 134 simulations have been carried out. Metamodels of the solar fraction have been then established for three ranges of the collector area; namely, 2–10 m2; 10–20 m2 and 20–30 m2. The results have shown that the solar fraction is highly dependent on the collectors’ area and the storage volume. Furthermore, the impact of the pump control strategy on the solar fraction has increased with larger systems. Finally, optimum design parameters have been obtained using the fitted models to achieve the targeted solar fraction of 60%. The proposed approach could be used for the optimization of solar heating systems design.
The purpose of this study is to formulate a steel fibre reinforced self-compacting concrete (SFSCC) that has optimal rheological and mechanical properties, using marble powder as an addition and ...partial substitution to cement. The design of experiments method (DOE) was used to analyse the effect of fibre dosage (%f), paste volume (V
p
) and the gravel/sand ratio (G/S) on the SFSCC. A concrete rheometer is used to quantify the intrinsic rheological parameters. The rheological results of the SFSCC show that the flow capacity decreases with increasing fibre dosage. By against the increase in the volume of the paste (V
p
) and the (G/S) ratio decreases the yield stress to give better performance to flow. The plastic viscosity is governed exclusively by the volume of the paste. Mechanical results showed that the volume of the paste has a significant influence on the flexural strength as well as the compression strength. Moreover, significant improvement in flexural strength is recorded when the three parameters (%f, V
p
and G/S) increase. Also, the ductility of SFSCC increases with increasing fibre dosage, while the compressive strength is little affected by the latter.
Summary
Due to the increasing need for drinking water in the world, various membrane processes have been developing significantly over the past several years. The process of membrane distillation is ...one of the non‐isothermal processes that cause steam to pass from the membrane due to the difference in temperature and the resulting difference in vapor pressure. Due to the lack of precision in the amount of flux and thermal efficiency in various operating conditions the membrane distillation process still needs development. This article attempted to examine the effects of flowrate, temperature, and module length on the performance of the membrane distillation process using computational fluid dynamics simulation and experiments design method. Since each of these parameters interacts with other parameters, the design of experiments method was used for numerical modeling of flux and thermal efficiency. The results showed that increasing flowrate, inlet feed temperature, and decreasing length of the membrane module increase the water flux and thermal efficiency. Numerical flux modeling results show that temperature (T), module length (L), and interaction module length‐temperature (L‐T) parameters have the most influence on flux and module length (L), temperature (T) and quadratic relation of module length (L2) parameters have the greatest effect on thermal efficiency, respectively.
CFD simulation of Direct Contact Membrane Distillation (DCMD) process and numerical modeling the effect of flowrate, feed temperature, and module length parameters on flux and thermal efficiency by design of experiments method.
The present research consists of studying the characterization and treatment of the olive mill wastewater (OMWW) resulting from the olive industries of the region of Loukkos, Morocco. According to ...the national plan for green Morocco, the annual volumes of OMWW discharges increase with the expansion of the areas of olive plantations compared to agricultural activities. The study of the organic, mineral, and microbiological composition of the obtained OMWW showed that they are rich in microbiological (FMAT, Let M., and B.L.), mineral (total Kjeldhal nitrogen, orthophosphate, total phosphorus, sodium, potassium, calcium, copper, iron, zinc, manganese, and lead ions), and organic (COD, BOD
5
, and polyphenols) micropollutants with very high percentages that are higher than the standards in force. The treatment used in this study is the combined process of aerated lagooning/adsorption using powdered activated carbon after optimization of the experimental parameters (mass concentration of activated carbon (AC) and agitation rapidity (Ar)) by experiment design method. The obtained physicochemical parameters, such as pH, total suspended solids (TSS), chemical oxygen demand (COD), rate of discoloration, and polyphenol content of raw OMWW, were 4.87, 0.63, 80.3, 0.8, and 1.45 g/l, respectively. The results of these parameters for the treated OMWW were obtained in the order of 6.10, 0.22, 28, 0.28, and 0.44 g/l for pH, TSS, COD, discoloration rate, and polyphenol content, respectively. These results show that the proposed treatment significantly reduced acidity, TSS, COD, discoloration rate, and polyphenol contents, with a performance of about 25.26, 65, 65.13, 65, and 69.65%, respectively. This indicates that there is significant performance in the processing of exploited OMWW.
The meaning of technological progress is to produce economic development and to increase the level of personal comfort. Sustainability can only be achieved if, at the microsystem level as well as at ...the macrosystem level, the secondary effects of the activities undertaken by people on the environment are in a state of neutrality compared to the impact they can produce on natural conditions. This neutrality can be intrinsic or can be achieved through coercive and compensatory measures. If we take into account the production of carbon dioxide that accompanies a product from the stages of conceptualisation, design, procurement of materials, execution, operation, maintenance, decommissioning and recycling the waste produced at the end of use, then nothing can be sustainable in pure form. Nevertheless, there are products whose production, both as a raw material and as a technological process, can be neutral in terms of carbon emissions. Moreover, they can even become carbon negative over time. This is also the case with eco-sustainable hemp concrete, whose capacity to absorb carbon dioxide starts from the growth phase of the plant from which the raw material is obtained and continues throughout the existence of the constructed buildings. Not only does it absorb carbon dioxide, but it also stores it for a period of at least 50 years as long as the construction is guaranteed, being at the same time completely recyclable. However, in order to obtain an optimal mixture from the point of view of raw material consumption, represented by industrial hemp wood chips and the binder based on lime and cement, multiple experiments are necessary. The study presented in this work is based on the use of an advanced method of experimental planning (design of experiments method), which makes possible the correlation between the values obtained experimentally and the algorithm that generated the matrix arrangement of the quantities of materials used in the recipes. This approach helps to create the necessary framework for parametric optimisation with a small number of trials. Thus, it is possible to obtain the mathematical law valid within the minimum and maximum limits of the studied domain that defines the characteristics of the material and allows the achievement of optimisation. The material is thus designed to satisfy the maximum thermal insulation requirements that it can achieve depending on a certain minimum admissible compressive strength.
The Kyoto protocol binded the developed countries to reduce the greenhouse gas emissions at least by 5% by 2008–2012 in order to tackle global warming and climate change. Some of the measures of the ...governments to achieve this goal are to promote new buildings construction and to retrofit existing buildings while satisfying low energy criteria. This means improving energy efficiency of buildings and energy systems, developing sustainable building concepts and promoting renewable energy sources.
The design of a low energy building requires parametric studies via simulation tools in order to optimize the design of the building envelope and HVAC systems. These studies are often complex and time consuming due to a large number of parameters to consider. Hence, this paper aims to set up a methodology that simplifies parametrical studies during the design process of a low energy building. The methodology is based on the Design of Experiments (DOE) method which is a statistical method widely used in industry to perform parametric studies that reduces the required number of experiments.
This paper reported on the work performed to study the formation of silicon nitride and silicon carbide whiskers using the carbothermal nitridation process. A distinctive aspect of the present study ...lies in the use of the mechanical milling method to alter the regularity of the crystalline network of the silica sand. In order to optimise the processing parameters for the synthesis of silicon carbide, the concept of Taguchi's Design of Experiments was considered, the analysis being based on Taguchi's signal to noise ratio and variance techniques to obtain optimum combination of process parameters. Important factors influencing the formation of silicon carbide were the duration of the mechanical milling, followed by temperature, time and heating rate.
PDF
