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Browsing Articles by Author "Adair, Desmond"
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Item Open Access Advanced Numerical Solver for Dam-Break Flow Application(Eurasian chemico-technological journal., http://www.researchgate.net/publication/283813681, 2012-01) Hui Pu, Jaan; Bakenov, Zhumabay; Adair, DesmondIn this paper, a HLL (Harten Lax van Leer) approximate Riemann solver with MUSCL scheme (Monotonic Upwind Schemes for Conservative Laws) is implemented in the presented FV (Finite Volume) model. The presented model is used to simulate different dam-break flow events to verify its capability. Four test cases are presented in this paper. In the first test case, a 1-Dimensional (1D) dambreak flow is simulated over a rectangular channel with different slope limiters of the FV model (namely Godunov, Superbee, Minmod, van Leer, and van Albada). The second test case consists of a simulation of shallow water discontinuous dam-break flow over a dry-downstream bed channel. The third test simulates the shallow water dam-break flow with the existence of bed slope and bed shear stress. Finally, in the last test, the HLL-MUSCL model used in this paper and some other solver models used in literature are compared against the referred exact solution in dam-break flow application. The presented HLL-MUSCL scheme is found to give the best agreement to the exact solution.Item Open Access Application of CFD modelling to air quality in Kuwait City(Springer, 2016-11-30) Zhunussova, Meruyert; Jaeger, Martin; Adair, DesmondHigh-resolution computational fluid dynamics (CFD) simulations have been performed to assess the dispersion of air pollutants (CO2) emanating from traffic in a busy street and in the vicinity of a complex configuration of buildings located in Salmiya, Kuwait City. New buildings are planned for this area, and the work here includes predictions for the dispersion of pollutants after the buildings’ completion. The CFD simulations are based on calculated CO2 concentration levels for traffic counts taken on location in Salmiya with the existing configuration of buildings. As the computer code used in this work has been evaluated previously, it will be applied here to predict with confidence any potential air pollution problem areas on the addition of the new buildings. It was found for very light wind, that the proposed new buildings help reduce pollution in the vicinity of residential buildings within the configuration of buildings, but as the wind becomes moderate to strong, there was a tendency for the pollutant to get trapped in the residential area. Results are given for both exceptionally high ambient temperatures and very light wind, which are not often reported in studies found in the literature.Item Open Access Assessment of a Shallow Water Model using a Linear Turbulence Model for Obstruction-Induced Discontinuous Flows(2012) Pu, Jaan Hui; Bakenov, Zhumabay; Adair, DesmondAssessment of the performance of a shallow water model with closure using a linear k-ε turbulence model is made for various obstruction-induced discontinuous flows. The monotone upwind scheme of conservative laws (MUSCL) - Hancock scheme is used, together with the Harten Lax van Leer (HLL) approximate Riemann solver in the discretization of the finite volume shallow water model. These kinds of models contribute to the improvement of optimized design of various processes in chemical engineering and technology. Two obstructed flow applications are presented, namely, single obstruction and multiple obstruction induced discontinuous flows; and the ability of the shallow water model with the k-ε based turbulence model to predict these applications are assessed. The simulation results of the shallow water model are compared with those found by direct numerical simulation (DNS) and experimental measurements in the literatureItem Metadata only Building on a traditional chemical engineering curriculum using computational fluid dynamics(Education for Chemical Engineers, 2014-12-01) Adair, Desmond; Bakenov, Zhumabay; Jaeger, Martin; Desmond, AdairAbstract Computational fluid dynamics (CFD) has been incorporated into a chemical engineering curriculum at the intermediate undergraduate level. CFD has now become a component of professional life in engineering practice and to prepare students properly, they must get exposure to all aspects of their chosen profession. Issues of concern arise when mathematical modelling is being introduced into a curriculum. For example, at the practical level, it must be considered whether or not an appropriate platform has been developed to allow the students to use the software efficiently and importantly without frustration. Also it is important that students have been taught sufficient skills for the student to continue with simulations in a systematic and methodical manner. The incorporation of the CFD package into a traditional chemical engineering curriculum is described here, and evaluation results based on pre–post knowledge and skill experiments, and student survey results document successful learning outcomes and effectiveness of the approach.Item Metadata only Conceptual design of a high-endurance hybrid electric unmanned aerial vehicle(Materials Today: Proceedings, 2017-01-01) Jaeger, Martin; Adair, Desmond; Martin, JaegerAbstract Small electric unmanned aerial vehicles (UAVs) have the advantages of low visual, heat and acoustic signatures, but have only limited flight endurance. For electric motor/battery powered UAV designs, to increase the flight endurance means an increase in the weight of the onboard battery, which in turn adds to the overall weight of the UAV and hence more power is used, especially during the ascent and possibly loiter stages of the mission. A marked increase in an aircraft’s endurance can be achieved with the inclusion of an internal combustion engine in the design, but this will result in high noise levels and possibly, an unwanted heat signature. The objective of this preliminary work is to show the feasibility of combining the two power sources, an internal combustion engine and electric motor to obtain a hybrid-electric UAV which will provide high flight endurance capability together with low visual/heat/acoustic signatures.Item Open Access Developing an Understanding of the Steps Involved in Solving Navier– Stokes Equations(2015) Adair, Desmond; Jaeger, MartinThis article describes how Mathematica can be used to develop an understanding of the basic steps involved in solving Navier– Stokes equations using a finite-volume approach for incompressible steady-state flow. The main aim is to let students follow from a mathematical description of a given problem through to the method of solution in a transparent way. The wellknown “driven cavity” problem is used as the problem for testing the coding, and the Navier–Stokes equations are solved in vorticity-streamfunction form. Building on what the students were familiar with from a previous course, the solution algorithm for the vorticity-streamfunction equations chosen was a relaxation procedure. However, this approach converges very slowly, so another method using matrix and linear algebra concepts was also introduced to emphasize the need for efficient and optimized codeItem Open Access Environmental impact of developing large buildings close to residential environments(Institute of Electrical and Electronics Engineers Inc., 2016-02-03) Zhunussova, Meruyert; Jaeger, Martin; Adair, DesmondHigh-resolution computational fluid dynamics (CFD) simulations have been performed to access the dispersion of air pollutants (CO2) emanating from traffic in a busy street and in the vicinity of a complex configuration of buildings located in Salmiya, Kuwait City.Item Open Access Locating air quality monitoring stations utilizing computational fluid dynamics(Institute of Electrical and Electronics Engineers Inc., 2016-04-05) Jaeger, Martin; Adair, Desmond; Zhunussova, MeruyertWith the advancement of high-resolution Computational Fluid Dynamics (CFD), measurements of variables related to the urban environment, such as air quality, can be optimized. Regarding smart solutions for the future cities, CFD allows for the optimizing of location for instrumentation to monitor air quality in order to facilitate optimized measures to counteract any potential detrimental effect on the local populations' health, at relatively low cost. To illustrate the power and efficiency of CFD this paper reports on a study in Kuwait of the dispersion of CO2 gas.Item Metadata only Nickel Hexacyanoferrate Nanoparticles as a Low Cost Cathode Material for Lithium-Ion Batteries(Electrochimica Acta, 2015-12-01) Omarova, Marzhana; Koishybay, Aibolat; Yesibolati, Nulati; Mentbayeva, Almagul; Umirov, Nurzhan; Ismailov, Kairat; Adair, Desmond; Babaa, Moulay-Rachid; Kurmanbayeva, Indira; Bakenov, Zhumabay; Marzhana, OmarovaAbstract Potassium nickel hexacyanoferrate KNi[Fe(CN)6] (NiHCF) was synthesized by a simple co-precipitation method and investigated as a cathode material for lithium-ion batteries. The X-ray diffraction and transmission electron microscopy studies revealed the formation of pure phase of agglomerated NiHCF nanoparticles of about 20–50nm in size. The material exhibited stable cycling performance as a cathode in a lithium half-cell within a wide range of current densities, and a working potential around 3.3V vs. Li+/Li. The lithium ion diffusion coefficient in this system was determined to be in a range of 10−9 to 10−8 cm2 s−1, which is within the values for the cathode materials for lithium-ion batteries with high rate capability. Considering promising electrochemical performance and attractive lithium-ion diffusion properties of this material along with its economical benefits and simplified preparation, NiHCF could be considered as a very promising cathode for large scale lithium-ion batteries.Item Open Access On using splitter plates and flow guide-vanes for battery module cooling(Heat and Mass Transfer/Waerme- und Stoffuebertragung, 2016-03-15) Ismailov, Kairat; Adair, Desmond; Massalin, Yerzhan; Bakenov, ZhumabayThermal management of lithium-ion battery modules needs to be an integral part of the design process to guarantee that temperatures remain within a narrow optimal range. Also it is important to minimize uneven distribution of temperature throughout a battery module so as to enhance the battery life cycle, and, charge and discharge performances. This paper explores by simulation, the benefits of attaching thin surfaces extended into the near-wake of cylindrical lithium-ion cells, here termed integral wake splitters, and, of placing flow guide-vane in the vicinity of the near wake, regarding thermal management.Item Open Access Propeller wing aerodynamic interference for small UAVs during VSTOL(Israel Annual Conference on Aerospace Sciences, 2016) Adair, Desmond; Alimaganbetov, MergenThe goal of the present investigation is to gain a better understanding, using numerical simulation, of the aerodynamic interference between propeller and wing during different flight phases of a VSTOL unmanned-aerial-vehicle (UAV). The proposed UAV investigated here, tilts part of the wings together with the propellers and nacelles, with each of the propellers located inboard between wing-tip and fuselage.Item Metadata only Simulation of tapered rotating beams with centrifugal stiffening using the Adomian decomposition method(Applied Mathematical Modelling, 2016-02-15) Adair, Desmond; Jaeger, Martin; Desmond, AdairAbstract The Adomian modified decomposition method (AMDM) is employed for the free transverse vibration analysis of rotating non-uniform Euler-Bernoulli beams using several boundary conditions, rotation speeds, and beam lengths. The equation of motion includes the axial force due to centrifugal stiffening. The AMDM allows the governing differential equation to become a recursive algebraic equation and after additional simple mathematical operations on the model, the natural frequencies and corresponding closed-form series solution of the mode shape can be obtained simultaneously. The AMDM technique is systematic, so it is straightforward to modify the boundary conditions for specific cases. Comparisons with previously reported results demonstrated that the results obtained by the proposed method were in close agreement.