Aly Elzahaby

• Professor Emeritus at Tanta University, Faculty of Engineering

Several engineering equipment's and installations often operates under severe conditions such as elevated temperatures and high pressures in turbines, combustion furnaces and chambers, engines, generators, etc. This results in lessening the life time of such facilities. Hence, many efforts have been made to study the effects of such conditions with...

This paper discusses the effect of adding porous strips to the centrifugal compressor blades on its flow instabilities by eliminating the rotating stall phenomena and then extending the compressor operating range. Porous strips are added on the suction side of the impeller main blades, on certain predetermined locations in previous work [1]. a para...

الهدف من البحث هو دراسة وتحليل والتعين الدقيق للدفع المحورى علىالعضو الدوار فى الضواغط الطاردة المرکزية. نشرح العوامل التى تؤثر علىالدفع المحورى مثل زيادة الأحمال على ضاغط ثانى أکسيد الکربون عنأوضاع التشغيل التصميمية له . کما تتضمن العوامل تأثير وجود Fouling مع الغاز مما ينتج عنه تراکم على الأسطح الداخلية لدفاعات العضو الدوارفيتسبب فى زيادة الدفع ا...

the present experimental work shows an investigation and analysis of flow field around flanged diffuser which causes the increase of wind speed at wind turbine blades. Diffuser models with different flange angles are tested at subsonic open wind tunnel by using particle image velocimetry technique. The originated vortices behind the flange of the d...

A particle image velocimetry (PIV) technique has been used to analyze the flow characteristics behind a road vehicle with/without an air spoiler attached on the behind end and also to estimate its effect on the wake. A vehicle model scaled in the ratio of 1/18 is set up in the mid-section of a closed-loop wind tunnel. The Reynolds number based on t...

الملخصان معدل انتقال الحرارة والتوصيلية الحرارية هما من أکثر الخصائصالمباشرة والعملية لتقييم أداء المواد لنقل الحرارة ولا توجد طريقة واحدة يمکناعتمادها لقياس الخواص الحرارية للمواد ولکن تقتصر کل طريقة قياس لتحديدالتوصيلية الحرارية على نطاق محدد من قيم التوصيلية الحرارية ودرجاتالحرارة وأنواع معينة من المواد ولا يتم تطبيق طرق قياس التوصيلية الحراريةع...

Centrifugal compressors play an important role in many industries. Improving the efficiency of centrifugal compressors and extending their range has been an important subject for both engineers and researchers working in the turbomachinery field. This paper discusses the optimization of Eckardt O impeller through changing its blade angles distribut...

This paper describes the automation of preliminary 3D aerothermodynamic design and analysis of a single-stage axial flow turbine driving the compressor of the micro turbojet engine Jet Cat p200 using an analytical method. The geometrical parameters of the new design are based on the reverse engineering of the small gas turbine. Baseline stage d...

The combustion process in the Premixed Charge Compression Ignition (PCCI) engine is basically restricted by the in cylinder charged mixture components. Also, the homogeneity of the charged mixture is determining the quality and process of the chemical reaction during the first stage of combustion which establish the auto-ignition process. In the pr...

Engineering can be defined as the career involved in designing, manufacturing, constructing, and maintaining of products, structures, and systems. It can be divided into two divisions including forward and reverse engineering. Forward engineering is considered to be the traditional method in performing a design process which starts from the require...

This paper describes the automation of 3D design and aerothermodynamic analysis of a high pressure, single-stage axial flow turbine driving the compressor of the small gas turbine engine Jet Cat p200 using an analytical method. The specifications of design are based on the reverse engineering of the small gas turbine. Baseline design parameters suc...

The present study shows a development and analysis of 2-D axisymmetric CFD model of flanged diffuser that was used as a casing for developed small wind turbines to increase the generated power. The 2-D CFD diffuser model grids are developed by GAMBIT, while the flow field analysis has been carried out using commercial software FLUENT. This study fo...

A micro turbojet engine is modeled using energy and momentum equations, which are solved to predict its performance and the flow parameters across it at design conditions. In order to simulate the engine's performance at off-design conditions, the complete performance maps of the different engine components are required. Therefore, empirical equati...

Jet noise remains a significant noise component in modern aero-engines. A high-speed flow mixing with the surrounding air constitutes noise sources behind the nozzle. This book consists of two parts. The first part is to provide an overview of the aircraft noise generating sources with emphasis on the jet noise, the main technologies employed for c...

Vibrations of turbomachinery blades are critical to jet engine durability and performance. Active vibration control using piezoelectric sensors and actuators have recently been emerged as a practical and promising technology. This book deals with a new vibration damping technique for an unmanned aerial vehicle (UAV) propeller (BIELA 24 in diameter...

published in International journal of scientific & engineering research(IJSER)

Vibrations of turbomachinery blades are critical to jet engine durability and performance. Active vibration control using piezoelectric sensors and actuators have recently been emerged as a practical and promising technology. This paper deals with a new vibration damping technique for an Unmanned Aerial Vehicle (UAV) propeller (BIELA 24 in diameter...

The new generation of smart materials and structure technologies featuring at the most sophisticated level a network of sensors and actuators, real time control capabilities, computational capabilities and a host structural material. Smart materials are usually attached or embedded into structural systems to enable these structures to sense disturb...

Jet noise remains a significant noise component in modern aero-engines. A high-speed flow mixing with the surrounding air constitutes noise sources behind the nozzle. One noise-reduction technology is expected to enhance mixing within a limited region downstream of the nozzle. The enhanced mixing leads to the suppression of broadband peak component...

It is well-established that minimizing water depth is one of the most vital key features to enhance the performance of solar stills. Accordingly, the performance of most recent attempts and proposed ideas tackling this point is limited. Thus, this work introduces a new approach that permits governing the water depth as desired and simultaneously ev...

Investigation of a novel parameter that considerably enhances the performance of disk oil skimmers is introduced. This is of a great significance for the contingency plans of removing oil spills from aquatic environments and deciding their scenarios. Efficiency of a conventional disk oil skimmer could be nearly doubled by careful optimization of th...

A new design of a stepped solar desalination system with flashing chamber is experimentally investigated. The main objective of the investigation was to study the performance of step-wise water basin coupled with a spray water system by augmenting desalination productivity through using two air heaters. The effect of using the spray system for seaw...

In this work Artificial Neural Networks (ANN) technique has been used to predict NOx emissions and Indicated Thermal Efficiency (ITE) for a direct injection Hydrogen engine, which is equipped with water direct injection system for NOx control. ANN has been used as a mathematical tool that learns from the experimental data obtained under different o...

The present work examines experimentally the effect of different direct water injection strategies on NOx emissions and performance in a direct injection hydrogen fueled engine. Three water injection strategies were considered including; injection at the suction, compression and expansion strokes. Both injection timing as well as quantity were vari...

In the present study, the interaction between a large number of adhering surfaces and spilled oil was experimentally studied throughout an extensive research program aiming toward enhancing the performance of the oleophilic disk skimmers commonly applied for recovery of oil spills from aquatic environment. Therefore, nine kinds of materials with di...

In this paper, an evaluation of the gas turbine bearing situation near and under temperature alarm is presented. A fuzzy synthetic decision-making system is used as a predictive maintenance procedure to make diagnosis by ferrographic analysis for real data taken from a turbine bearing. Analyzing the wear debris, the bearing failure start is detecte...

In the present work, theoretical and experimental evaluation of the effect of bed configuration and operating conditions on the performance of desiccant dehumidification system has been carried out. A new rotating absorption disk has been designed and constructed to be tested in the experimental work. The desiccant wheel has a cylindrical shape of...

The cycle-to-cycle variation in the flow field inside a four stroke ignition engine has been studied. The particle image velocimetry (PIV) technique has been used to measure the flow field inside the engine. The measurements have been carried out in a motored engine equipped with suitable access. The measurements have been carried out in both the s...

A Solar desalination system with flashing chamber is experimentally investigated. It was found that the productivity and performance of the system were significantly positive dependent on both the mass flow rate of the impure water and the linear speed of the nozzle's holder, and slightly increase with the using of a porous medium in basin of the s...