Sensorless Fuzzy Direct Torque Control for High Performance Electric Vehicle with Four In-Wheel Motors

M’hamed Sekour,Kada Hartani,Azeddine Draou,Ahmed Allali 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.3

This paper describes a control scheme of speed sensorless fuzzy direct torque control (FDTC) of permanent magnet synchronous motor for electric vehicle (EV). Electric vehicle requires fast torque response and high efficiency of the drive. Speed sensorless FDTC In-wheel PMSM drives without mechanical speed sensors at the motor shaft have the attractions of low cost, quick response and high reliability in electric vehicle application. This paper presents a new approach to estimate the speed of in-wheel electrical vehicles based on Model Reference Adaptive System (MRAS). The direct torque control suffers in low speeds due to the effect of changes in stator resistance on the flux measurements. To improve the system performance at low speeds, a PI-fuzzy resistance estimator is proposed to eliminate the error due to changes in stator resistance. High performance sensorless drive of the in-wheel motor based on MRAS with on line stator resistance tuning is established for four motorized wheels electric vehicle and the whole system is simulated by matalb/simulink. The simulation results show the effectiveness of the new control strategy. This proposed control strategy is extensively used in electric vehicle application.

Acid modified local clay beads as effective low-cost adsorbent for dynamic adsorption of methylene blue

M. Auta,B.H. Hameed 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4

Locally sourced clay was harnessed to study its adsorptive potential of methylene blue (MB) in wastewater streams. The clay was modified with sulfuric acid and aluminum hydroxide. The raw and modified freeze dried clay bead RHC and MHC were subjected to batch and batch/fixed-bed adsorption studies, respectively. Elemental analysis, morphological structures were determined, and surface area of 19.3 (RHC) and 101.2 (MHC) m2/g were obtained. Langmuir, Freundlich and Redlich–Peterson isotherms models were analyzed and the modification increased adsorption capacity from 58.02 to 223.19 mg/g at 30 8C. The MB adsorption on RHC/MHC was spontaneous, exothermic and obeyed pseudo-second-order model.

Sorption of chlorophenols on geotextile of the geosynthetic clay liners

M"hamed Ahari,Nathalie Touze-Foltz,Laurent Mazeas 대한환경공학회 2020 Environmental Engineering Research Vol.25 No.2

Knowledge of organic micropollutant transfers in barrier seal materials from waste storage facilities is limited to volatile organic compounds and phenolic compounds at ambient temperature. This study focused on the sorption of chlorophenols (CPs) from various geotextiles from clay geosynthetics under the influence of temperature. Also to study the impact of the polarity or the amount of CPs adsorbed on geotextiles with the partition coefficient. The effect of various parameters such as contact time, effect of temperature, initial CPs concentration and adsorbent dosage has been carried out in this study. The result obtained is non-linear and the data was calculated for affinity with Freundlich isotherm model. An important observation is that the amount of CPs sorbed on geotextiles increases with a growing number of chlorine atoms, ie increases with the partition coefficient (log Kow). During this study, a decrease in adsorbent properties was observed with the rise in temperature from 23°C to 55°C. The partitioning coefficients for CPs examined range are from 2.4 (R² = 0.86) to 8.4 mL/g (R² = 0.90). Among the CPs studied, the highest adsorbed quantity was observed for pentachlorophenol with 0.052 g/g at 23°C, this quantity will decrease with the increase in temperature.

Study of the rheological behavior of mortar with silica fume and superplasticizer admixtures according to the water film thickness

M’hamed Adjoudj,Karim Ezziane,El Hadj Kadri,Hamza Soualhi 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.7

In the manufacture of mortar or concrete, the mixing water fills the interstitial voids between the solid particles of cement and thevolume of the resulting paste should be more than sufficient to fill the voids between the fine and coarse aggregates. So we shouldhave enough water to cover all the fine particles and enough paste to cover all aggregates. Therefore, it can be assumed that bothWater Film Thickness (WFT) and paste film thickness have major effects on the rheology of the mortar. In this work, we try to applythis approach to understand the rheological properties of mortars containing various amount of Silica Fume (SF) with two types ofsuperplasticizer using rheometer apparatus and mini cone test. The results show that the rheological behavior is governed by waterfilm thickness and the dosage of superplasticizer. However, for high dosages water film thickness remains the only factor governingthe behavior. In addition, the mixture compactness increases significantly when adjuvanted with efficient superplasticizer.

Numerical Study of Fan Coil Heat Exchanger with Copper-Foam

Ahmed M. Hassan,Adil Abbas Alwan,Hameed K. Hamzah 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.1

Due to its high porosity as well as a high specific surface area, the use of open cell metallic foam in heat transfer applications has received increasing interest. In present study, the dynamic and thermal performance of heat exchanger composed of copper foam incorporated in a fan coil was numerically analyzed. Darcy-Brinkman-Forchheimer model was used to represent the momentum equation inside the metallic foam (a porous medium). A local thermal equilibrium was used to solve the energy equation through the porous medium. Different porosity values were taken during the study, ranging from 0.88 to 0.98, while the velocity of inlet air of the heat exchanger ranged from 1 m/s to 10 m/s. The objective of current study is to compare the thermal and dynamic performance of the heat exchanger affected by several variables such as heat transfer coefficient, friction factor, pressure drop, Colburn factor, and area goodness factor. The results showed that increasing the air inlet velocity will increase the heat transfer coefficient, but on the other hand, increasing the velocity ten times will rise pressure drop from 19.032 Pa to 335.76 Pa. Also, the area goodness factor value will decrease with increasing inlet velocity. Finally, we found that increasing in medium porosity will reduce heat transfer coefficient but increase pressure drop

Physical Characteristics of Small Space Objects at High Orbits Based on Optical Methods

Afaf M. Abd El-Hameed,Gamal F. Attia,,Yehia Abdel-Aziz 한국우주과학회 2017 Journal of Astronomy and Space Sciences Vol.34 No.1

Optical observation is one of the most common techniques used for characterizing the physical properties of unknown objects and debris in space. This research presents measurements and properties of the new object 96019 from ground-based optical methods. Optical observations of this small object were performed using a charge-coupled device (CCD) camera and the Santel-500 telescope at the Zvenigorod Observatory. The orbital elements and physical properties of this object, such as areato- mass ratio, have been determined. The results show that this small object has a low area-to-mass ratio, between 0.009 and 0.12 m2/kg. The light curve of object 96019 is given: Over the time intervals, variations in brightness are analyzed and the maximum brightness was found to be 12.4 magnitudes. The observational results show that, this object brightens by about three magnitudes over a time span of three minutes. Based on these observations, the characteristics and physical properties of this object are discussed.

Improvement of Underlay Cooperative Cognitive Networks Bandwidth Efficiency under Interference and Power Constraints

( Hameed R. M. Al-mishmish ),( Barbaros Preveze ),( Ahmed Alkhayyat ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.11

The definition of the bandwidth efficiency (BE) of cognitive cooperative network (CCN) is the ratio between a number of the licensed slot(s) or sub-channel(s) used by the unlicensed users to transmit a single data packet from the unlicensed transmitter to unlicensed destination, and from unlicensed relay(s) to unlicensed destination. This paper analyzes and improves the BE in the underlay CCN with a new reactive relay selection under interference and power constraints. In other words, this paper studies how unlicensed cooperative users use the licensed network slot(s) or sub-channel(s) efficiently. To this end, a reactive relay selection method named as Relay Automatic Repeat Request (RARQ) is proposed and utilized with a CCN under interference and power constraints. It is shown that the BE of CCN is higher than that of cooperative transmission (CT) due to the interference and power constraint. Furthermore, the BE of CCN is affected by the distance of the interference links which are between the unlicensed transmitter to the licensed destination and unlicensed relay to the licensed destination. In addition, the BE for multiple relays selection over a CCN under interference and power constraints is also analyzed and studied, and it is shown that the BE of CCN decreases as the number of relays increases.

Thermodynamic Investigation of Integrated Air Cycle Refrigeration Systems

Hamed Shoul,Mehran Ameri,S. M. Hojjat Mohammadi 대한설비공학회 2017 International Journal of Air-Conditioning and Refr Vol.25 No.2

An analysis of air cycle refrigeration (ACR) systems based on the first and second laws of thermodynamics has been carried out. Cooling the gas cooler outlet enhances the system efficiency, hence the use of integrated refrigeration systems (IRSs). The IRS consists of an ACR, an absorption chiller and a prime mover. The waste heat from the prime mover operates the absorption chiller, which provides additional cooling that is used to cool down the air exiting the gas cooler. LiBr-H2O and NH3-H2O are used as fluid pairs in absorption section. The prime mover can either be gas turbine or solid oxide fuel cell (SOFC). Results indicate that an IRS with NH3-H2O and two recuperators has a better first and second law efficiency compared to other considered systems. It is also concluded that the energy utilization factor and second law efficiency are higher for the system with SOFC as a prime mover.

Studies on Υ-irradiated polymer–nano calcined clay blended cement mortar composites

M.R. Ismail,E. Hamed,H.A. Abdel-Rahman,M.M. Younes,S.H. El-Hamouly 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

This study focuses on the preparation of blended cement mortars by a partial replacement of Portland cement by different ratios of nano-calcined clay. Also, the addition of PVA on blended cement mortar with different percentages. In addition to the influence of different doses of gamma rays on the physicochemical properties of the blended cement composites; the specimens are cured under tap water. Results showed that, compressive strength and bulk density of the composites increased with increasing the irradiation dose and PVA contents for certain values while, total porosity behaved in an opposite direction. XRD, SEM, TGA confirmed these conclusions.

Displacement Measurements Around Crack Tips by Digital and Conventional Laser Speckle

M. H. Hamed 대한기계학회 1990 KSME International Journal Vol.4 No.1