Saud Ghani

A numerical investigation into the feasibility of integrating green building technologies into row houses in the Middle East

A traditional row house was re-designed to be adapted to the hot and arid climate of the Middle East. The vernacular design features include a number of cooling devices such as an open courtyard, wind towers and heat-storing building materials to reduce overheating during the summer months. This paper reports on the results of a computational fluid dynamics (CFD) modelling study of the performance of a wind tower incorporated into the row house to replace the traditional ventilation devices. The study investigated the ways in which the resulting natural air flows in the house operated using the ANSYS Fluent CFD tool to develop a numerical model of an optimized wind tower system. Achieved ventilation rates and temperature distribution inside the structure were investigated. The results demonstrated that the proposed wind tower configuration was able to increase the average indoor air velocity by 63%. An improved airflow distribution is observed inside the modified row housing model.

Optimization of reliability and maintenance of liquefaction system on FLNG terminals using Markov modelling

Purpose – The purpose of this paper is to optimize system redundancy and maintenance intervals of a propane pre-cooled mixed refrigerant (C3MR) liquefaction process on floating liquefied natural gas (FLNG) export platforms. Design/methodology/approach – The reliability modeling is based on the time-dependent Markov approach. Four different system options are studied, with various degree of redundancy. Failures in the liquefaction system usually lead to shutdown the whole LNG production plant. The associated shutdown cost is compared with the cost of introducing redundancy and the cost of onboard maintenance. To ensure a high profitability, a model for maintenance optimization is utilized and applied to the main unit of the C3MR liquefaction system to minimize the onboard maintenance cost. Findings – The results indicated that the introduction of a second liquefaction system (as a standby unit) is the best option for liquefaction plant in terms of reliability and cost. This will substantially reduce the un...

A numerical investigation into the feasibility of a passive-assisted natural ventilation stack device

Various commercially available natural ventilation devices supply fresh air without mechanical assistance. These devices offer a low-energy alternative to mechanical air handling units. However, they often cannot satisfy recommended ventilation rates due to their dependence on both macro- and microclimate wind speeds. This work examines the feasibility of achieving the recommended fresh air delivery rates without impacting on the device energy requirements. A numerical investigation is carried out using a standard passive stack device geometry combined with a simulated low-powered axial fan. The investigation shows that a low-induced pressure of 20 Pa is enough to satisfy the legislative requirements. Depending on the macroclimate conditions, this induced pressure could be generated from a commercially available solar-powered system. As the fan system is only used in periods of low external wind velocities (1 m/s), it is termed a passive-assisted stack.

Design of Qatar University's first solar car for Shell Eco-marathon competition

Research and development in the area of renewable energy is growing fast, supported by the increasing awareness about sustainability, environment and limitation of conventional sources of energy. Interestingly, oil and gas companies are realizing the potential of renewable energy, and have been supporting events and competitions that aim precisely at developing technologies and expertise for this field. Shell is one of these companies; it has been organizing the yearly Shell Eco-marathon competition in three continents for decades now. Qatar Universitys students have participated in the latest edition of the race in the solar car category, held in Germany in May 2011. The team was made up of electrical and mechanical engineering students form the both departments. In this first participation, the aim was to design the first prototype of energy efficient solar and GTL cars to be starter point for a regular participation in future races. This paper discusses all the designing steps, components selection, measurements, calculations and manufacturing process that led to the first prototype of the solar car. A brief is given about the lessons learnt from the first participation and about the plans for the next participation in Shell Eco-marathon Asia in Malaysia in July 2012.

Thermal comfort investigation of an outdoor air-conditioned area in a hot and arid environment

Thermal comfort in hot and arid outdoor environments is an industrial challenging field. An outdoor air-conditioned area was designed and built to host sport and social events during summers 2014 and 2015 in Qatar. This article presents a thermal comfort analysis of the outdoor air-conditioned area using computational fluid dynamics, on-site spectators surveys, and on-spot climatic measurements. The study utilized computational fluid dynamics to develop a thermal comfort model of the outdoor air-conditioned area to predict the thermal comfort of the occupants. Five different thermal comfort indices; mean comfort vote, cooling power index, wet-bulb globe temperature index, Humidex, discomfort index, were utilized to assess the thermal comfort of spectators within the conditioned space. The indices utilized different on site measurements of meteorological data and on-site interviews. In comparison to the mean comfort vote of the sampled survey, all thermal comfort indices underestimated the actual thermal comfort percentage except the wet-bulb globe temperature index that overestimated the comfort percentage. The computational fluid dynamics results reasonably predicted most of the thermal comfort indices values. The computational fluid dynamics results overestimated the comfort percentage of mean comfort vote, wet-bulb globe temperature index, and discomfort index, while the thermal comfort percentage was underestimated as indicated by the cooling power index, and Humidex.

Performance Comparison Between Fast Fourier Transform-Based Segmentation, Feature Selection, and Fault Identification Algorithm and Neural Network for the Condition Monitoring of Centrifugal Equipment

This paper compares and evaluates the performance of two major feature selection and fault identification methods utilized for the Condition Monitoring (CM) of centrifugal equipment, namely FFT-based Segmentation, Feature Selection, and Fault Identification (FS2FI) algorithm and Neural Network (NN). Mutli-Layer Perceptron is the most commonly used NN model for fault pattern recognition. Feature-selection and Trending play an important role in pattern recognition, and hence, affect the performance of CM systems. The technical and developmental challenges of both methods were investigated experimentally on a Paxton industrial centrifugal air blower system with a rotational speed of 15,650 RPM‟s. Five different machine conditions were experimentally emulated in the laboratory. A low training-to-testing ratio of 50% was utilized to evaluate the performance of both methods. In order to maximize fault identification accuracy and minimize computing time and cost, a near-optimal NN configuration was identified. The results showed that both techniques operated with a fault identification accuracy of 100%. However, the FS2FI algorithm showed a number of advantages over NN. These advantages include the ease of implementation and a reduction of cost and time in development and computing, as it processed the data from the first trial in less than 6.2% of the time taken by the neural network.

Contribution of Shell Eco-Marathon engineering design experience to soft skills development: A qualitative analysis in the Asian context

Recent studies emphasize the needs of a wider set of skills engineers require than ever thought. Engineering curricula have been frequently criticized. Engineering design experience is one remedial way of heavy theory oriented curriculum. Many Universities started to integrate more design experiences in their curriculum. While a straight forward implication of integrating engineering design in engineering education is the development of higher order of technical and core engineering skills, a significant side outcome of impact of engineering design on soft skills development is barely investigated. Shell Eco-Marathon is a complex engineering design process, and is a competition oriented learning experience. This paper reports on the findings of qualitative investigation of the SEM impact on soft skills development of engineering students, with a case conducted within the Asian context.

Utilizing international design competitions for enhancing 21 st century engineering skills: The experience of shell Eco-Marathon

Nurturing design skills in students is in the heart of all engineering curricula. While academic courses and capstone activities inject the design process in students, involvement in practical design activities is believed to have higher impact on student preparation for engineering professions. Capitalizing on this fact, this paper aims to study the impact of Shell Echo-Marathon (SEM), an international engineering design competition, on engineering student learning at Qatar University (QU). The paper elaborates on the involvement of QU students in the competition and the experience accumulated over the years. In addition, impact measure methodology of the empirical investigation is highlighted together with the process of instruments development. This is followed by details on the investigation findings. The paper concludes the existence of positive impact of SEM on 21st century engineering competencies development, as well as, a shift in perceptions, confidence, and attitudes of engineering profession, engineering nature, and personal skills.

A Novel Impact Damper Consisting of a Linear Chain of Particles

Passive control is preferred due to its simplicity and low power consumption. A common passive control device is the Impact Damper which consists of a freely moving mass constrained by two stops inside a container mounted on the primary system. Researchers attempted to develop the impact damper for many decades. Their objective was to decrease the high accelerations, contact forces and noise levels.In this paper, a novel type impact damper consisting of linear chain of different sizes spherical balls is introduced. The Linear Particle Chain (LPC) impact damper is based on dissipating the kinetic energy of the primary system by placing a small ball between each two large balls in the chain arrangement. The small ball will have numerous collisions with the larger balls when the primary system is excited. This behavior leads to dissipate part of the kinetic energy at each collision with the large balls.The LPC impact damper is validated by comparing its responses with the single unit conventional impact damper. The free vibration of a single degree of freedom system equipped with the damper is studied. It has been shown that the LPC impact damper is more efficient than the conventional impact damper. A parametric study is conducted to investigate the effective number of balls and the efficient geometry of the impact damper to be used in a specific available space in the primary system.Copyright