We propose a reduced-order model for the instantaneous hydrodynamic force on a cylinder. The mode... more We propose a reduced-order model for the instantaneous hydrodynamic force on a cylinder. The model consists of a system of two ordinary differential equations (ODEs), which can be integrated in time to yield very accurate histories of the resultant force and its direction. In contrast to several existing models, the proposed model considers the actual (total) hydrodynamic force rather than its perpendicular or parallel projection (the lift and drag), and captures the complete force rather than the oscillatory part only. We study and provide descriptions of the relationship between the model parameters, evaluated utilizing results from numerical simulations, and the Reynolds number so that the model can be used at any arbitrary value within the considered range of 100 to 500 to provide accurate representation of the force without the need to perform timeconsuming simulations and solving the partial differential equations (PDEs) governing the flow field. Keywords—reduced-order model, ...
The Finite Volume Method in Computational Fluid Dynamics to numerically model a fluid flow proble... more The Finite Volume Method in Computational Fluid Dynamics to numerically model a fluid flow problem involves the process of formulating the numerical flux at the faces of the control volume. This process is important in deciding the resolution of the numerical solution, thus its quality. In the current work, the performance of different flux construction methods when solving the one-dimensional Euler equations for an inviscid flow is analyzed through a test problem in the literature having an exact (analytical) solution, which is the Sod problem. The work considered twenty two flux methods, which are: exact Riemann solver (Godunov), Roe, Kurganov-Noelle-Petrova, Kurganov-Tadmor, Steger-Warming Flux Vector Splitting, van Leer Flux Vector Splitting, AUSM, AUSM + , AUSM + −up, AUFS, five variants of the Harten-Lax-van Leer (HLL) family, and their corresponding five variants of the HartenLax-van Leer-Contact (HLLC) family, Lax-Friedrichs (Lax), and Rusanov. The methods of exact Riemann s...
With an increasing interest in launching artificial intelligence (AI) programs at higher educatio... more With an increasing interest in launching artificial intelligence (AI) programs at higher education institutions, both at the undergraduate level and the postgraduate level, a parallel interest in accrediting these programs locally and internationally should arise. This work considers two accreditation systems. One system is local in the Sultanate of Oman, and it is managed by the Oman Academic Accreditation Authority (OAAA), as per its current version (as of September 2020). The other system is recognized internationally, which has accredited programs in more than 30 countries, and it is managed by the U.S.-based non-governmental agency ABET. It is described here as per the 2020–2021 accreditation cycle of ABET, which is the current cycle (as of September 2020). Exploring the applicability of both systems to artificial intelligence programs, the following findings were reached: None of the systems has explicit customization for artificial intelligence specialization. The local Omani accreditation of an AI program comes after a 2-stage institutional accreditation first, with its two stages separated by about 4 years. On the other hand, ABET accreditation combines the institutional and the program assessments in one process. The OAAA program accreditation is available to both undergraduate and postgraduate degrees of artificial intelligence programs. ABET program accreditation applies only to bachelor programs of artificial intelligence.
International Journal of Management and Economics Invention
Since the start of its national renaissance in 1970, the Sultanate of Oman (Oman) has gone over a... more Since the start of its national renaissance in 1970, the Sultanate of Oman (Oman) has gone over a major development in several areas, such as education, infrastructure, and urbanization. This has been powered by the revenues from exporting crude oil and natural gas, which together form the skeleton of the country’s economy. In the second half of 2014, the oil prices declined strongly to about 50% of its price. This was followed by another moderate decline in the second half of 2015 and the beginning of 2016, leaving the barrel price at a low level below 30 US$ in January 2016 (as compared to above 110 US$ in June 2014). This drop had direct impacts on the economy of Oman, manifested in a large budget deficit, reduced governmental expenditure, reduced or cancelled subsidy of fuels and electricity, increase in the water tariff, and decline in deposits in banks. The country is coping with this through its 9th five-year plan (2016-2020), which adopts a strategy of diversifying the incom...
International Journal of Nonlinear Sciences and Numerical Simulation
When mathematically calculating the radiant heat flux during combustion, the radiant property of ... more When mathematically calculating the radiant heat flux during combustion, the radiant property of a gaseous mixture can be approximated as a weighted sum of the radiant properties of fictitious gases to give an equivalent effect of the actual gas mixture. This concept has been in use for many years. However, it was initially tailored to product gases in air-combustion environment. With the advent and progress in nitrogen-free combustion (particularly for environmental purposes), the chemical composition of the combustion gases is highly altered and existing models should be assessed for their suitability in these new environments. We carried out this task, which was motivated by our recent modeling work that revealed that a new model should be developed for nitrogen-free combustion environments. The model proposed here has four participating gases plus one transparent gas and its performance in predicting radiant heat transfer in 3D benchmark problems is evaluated in comparison with ...
This work represents a short statistical survey of the ABET accreditation in the 22 Arab countrie... more This work represents a short statistical survey of the ABET accreditation in the 22 Arab countries. The data about ABET accreditation are last-updated on October 1, 2017. We found that there are 11 Arab countries with ABET-accredited programs, totaling 358 programs. These programs are mostly at the bachelor level, and are housed in 62 institutions of higher education. In a descending order of the number of ABET accredited programs they have, these countries are: (1) Saudi Arabia, (2) United Arab Emirates, (3) Lebanon, (4) Kuwait, (5) Egypt, (6) Jordan, (7) Bahrain, (8 and 9) Palestine and Qatar, (10) Oman, and (11) Morocco. Only Saudi Arabia has ABET-accredited programs at the master’s level. Kuwait and Saudi Arabia are the only countries in the list that have ABET-accredited programs at the associate (diploma, 2-year) level. To account for the large variation of population for the considered countries, a relative scale for comparisons is introduced on a per-capita basis, and we cal...
We developed a vacuum generation system composed of a reciprocating compressor (3 tons of refrige... more We developed a vacuum generation system composed of a reciprocating compressor (3 tons of refrigeration) with an inverted-function that is ready to be hooked flexibly to a gas-tight container to create an evacuated enclosed atmosphere, without strict limitation of the size of that container. The evacuated container (or vacuum chamber) can serve in different purposes such as educational demonstration of the vacuum properties, extraction of perfumes from herbal resources, and preserving food. We tested the device and found it can reach a vacuum level of 26 inches of mercury in an environment with an atmospheric pressure of 28.5 inches of mercury. We compared the performance of our vacuum device to a rotary-vane vacuum pump of ¼ horsepowers and found that the vacuum pump reaches a set test vacuum level of 25 inches of mercury before the compressor. We then demonstrated experimentally some features of the vacuum using the inverted compressor or the vane vacuum pump. These experiments se...
Wseas Transactions on Signal Processing, Oct 1, 2008
... 11. E. Gröschel, W. Schröder, P. Renze, M. Meinke, and P. Comte, Noise Prediction for a Turbu... more ... 11. E. Gröschel, W. Schröder, P. Renze, M. Meinke, and P. Comte, Noise Prediction for a Turbulent Jet Using Different Hybrid Methods ... 21. RR Mankbadi, SH Shih, R. Hixon, and LA Povinelli, Direct Computation of Jet Noise Produced by Large-Scale Axisymmetric Structures ...
We studied various characteristics of the flow-induced vibration (FIV) of a spring-mounted cylind... more We studied various characteristics of the flow-induced vibration (FIV) of a spring-mounted cylinder, and the fluctuating lift and drag forces exerted on the cylinder due to the periodic changes in the fluid motion and vortex structure. We compared two conditions, which represent the limiting cases for the solid-to-fluid density ratio: the cylinder density is negligible relative to the fluid density, and the fluid density is negligible relative to the cylinder density. For both conditions, we examined the changes in these characteristics over a wide range of nondimensional mass-damping for one degree of freedom (1-DOF, cross-flow) and 2-DOF (cross-flow and in-line) vibration. The four cases exhibit differences (especially at low mass-damping) but also have some similarities in the characteristics of the FIV, induced forces, and energy extraction from the flow. We examined these differences and similarities, the implied errors when the in-line DOF is neglected, and the feasibility of ...
We perform direct numerical simulations of the flow past a circular cylinder undergoing a one-deg... more We perform direct numerical simulations of the flow past a circular cylinder undergoing a one-degree-of-freedom transverse oscillation. The displacement follows a sine function raised to an arbitrary integer power ranging from 1 to 8. When the displacement power is above 2, we have multifrequency oscillation, and the number of Fourier components in the oscillation increases with the power, but they are either odd or even multiples of the input (argument) frequency of the displacement function. We study the responses of the nondimensional lift and drag under these different oscillation profiles and the transfer of nondimensional mechanical energy due to the oscillation, and their trends as the power (hence the number of Fourier components in the oscillation) increases. For odd powers, the energy is transferred to the cylinder; whereas for even powers, it is transferred to the flow. A unity power (harmonic oscillation) corresponds to the maximum energy transfer to the cylinder, which ...
We propose a reduced-order model for the instantaneous hydrodynamic force on a cylinder. The mode... more We propose a reduced-order model for the instantaneous hydrodynamic force on a cylinder. The model consists of a system of two ordinary differential equations (ODEs), which can be integrated in time to yield very accurate histories of the resultant force and its direction. In contrast to several existing models, the proposed model considers the actual (total) hydrodynamic force rather than its perpendicular or parallel projection (the lift and drag), and captures the complete force rather than the oscillatory part only. We study and provide descriptions of the relationship between the model parameters, evaluated utilizing results from numerical simulations, and the Reynolds number so that the model can be used at any arbitrary value within the considered range of 100 to 500 to provide accurate representation of the force without the need to perform timeconsuming simulations and solving the partial differential equations (PDEs) governing the flow field. Keywords—reduced-order model, ...
The Finite Volume Method in Computational Fluid Dynamics to numerically model a fluid flow proble... more The Finite Volume Method in Computational Fluid Dynamics to numerically model a fluid flow problem involves the process of formulating the numerical flux at the faces of the control volume. This process is important in deciding the resolution of the numerical solution, thus its quality. In the current work, the performance of different flux construction methods when solving the one-dimensional Euler equations for an inviscid flow is analyzed through a test problem in the literature having an exact (analytical) solution, which is the Sod problem. The work considered twenty two flux methods, which are: exact Riemann solver (Godunov), Roe, Kurganov-Noelle-Petrova, Kurganov-Tadmor, Steger-Warming Flux Vector Splitting, van Leer Flux Vector Splitting, AUSM, AUSM + , AUSM + −up, AUFS, five variants of the Harten-Lax-van Leer (HLL) family, and their corresponding five variants of the HartenLax-van Leer-Contact (HLLC) family, Lax-Friedrichs (Lax), and Rusanov. The methods of exact Riemann s...
With an increasing interest in launching artificial intelligence (AI) programs at higher educatio... more With an increasing interest in launching artificial intelligence (AI) programs at higher education institutions, both at the undergraduate level and the postgraduate level, a parallel interest in accrediting these programs locally and internationally should arise. This work considers two accreditation systems. One system is local in the Sultanate of Oman, and it is managed by the Oman Academic Accreditation Authority (OAAA), as per its current version (as of September 2020). The other system is recognized internationally, which has accredited programs in more than 30 countries, and it is managed by the U.S.-based non-governmental agency ABET. It is described here as per the 2020–2021 accreditation cycle of ABET, which is the current cycle (as of September 2020). Exploring the applicability of both systems to artificial intelligence programs, the following findings were reached: None of the systems has explicit customization for artificial intelligence specialization. The local Omani accreditation of an AI program comes after a 2-stage institutional accreditation first, with its two stages separated by about 4 years. On the other hand, ABET accreditation combines the institutional and the program assessments in one process. The OAAA program accreditation is available to both undergraduate and postgraduate degrees of artificial intelligence programs. ABET program accreditation applies only to bachelor programs of artificial intelligence.
International Journal of Management and Economics Invention
Since the start of its national renaissance in 1970, the Sultanate of Oman (Oman) has gone over a... more Since the start of its national renaissance in 1970, the Sultanate of Oman (Oman) has gone over a major development in several areas, such as education, infrastructure, and urbanization. This has been powered by the revenues from exporting crude oil and natural gas, which together form the skeleton of the country’s economy. In the second half of 2014, the oil prices declined strongly to about 50% of its price. This was followed by another moderate decline in the second half of 2015 and the beginning of 2016, leaving the barrel price at a low level below 30 US$ in January 2016 (as compared to above 110 US$ in June 2014). This drop had direct impacts on the economy of Oman, manifested in a large budget deficit, reduced governmental expenditure, reduced or cancelled subsidy of fuels and electricity, increase in the water tariff, and decline in deposits in banks. The country is coping with this through its 9th five-year plan (2016-2020), which adopts a strategy of diversifying the incom...
International Journal of Nonlinear Sciences and Numerical Simulation
When mathematically calculating the radiant heat flux during combustion, the radiant property of ... more When mathematically calculating the radiant heat flux during combustion, the radiant property of a gaseous mixture can be approximated as a weighted sum of the radiant properties of fictitious gases to give an equivalent effect of the actual gas mixture. This concept has been in use for many years. However, it was initially tailored to product gases in air-combustion environment. With the advent and progress in nitrogen-free combustion (particularly for environmental purposes), the chemical composition of the combustion gases is highly altered and existing models should be assessed for their suitability in these new environments. We carried out this task, which was motivated by our recent modeling work that revealed that a new model should be developed for nitrogen-free combustion environments. The model proposed here has four participating gases plus one transparent gas and its performance in predicting radiant heat transfer in 3D benchmark problems is evaluated in comparison with ...
This work represents a short statistical survey of the ABET accreditation in the 22 Arab countrie... more This work represents a short statistical survey of the ABET accreditation in the 22 Arab countries. The data about ABET accreditation are last-updated on October 1, 2017. We found that there are 11 Arab countries with ABET-accredited programs, totaling 358 programs. These programs are mostly at the bachelor level, and are housed in 62 institutions of higher education. In a descending order of the number of ABET accredited programs they have, these countries are: (1) Saudi Arabia, (2) United Arab Emirates, (3) Lebanon, (4) Kuwait, (5) Egypt, (6) Jordan, (7) Bahrain, (8 and 9) Palestine and Qatar, (10) Oman, and (11) Morocco. Only Saudi Arabia has ABET-accredited programs at the master’s level. Kuwait and Saudi Arabia are the only countries in the list that have ABET-accredited programs at the associate (diploma, 2-year) level. To account for the large variation of population for the considered countries, a relative scale for comparisons is introduced on a per-capita basis, and we cal...
We developed a vacuum generation system composed of a reciprocating compressor (3 tons of refrige... more We developed a vacuum generation system composed of a reciprocating compressor (3 tons of refrigeration) with an inverted-function that is ready to be hooked flexibly to a gas-tight container to create an evacuated enclosed atmosphere, without strict limitation of the size of that container. The evacuated container (or vacuum chamber) can serve in different purposes such as educational demonstration of the vacuum properties, extraction of perfumes from herbal resources, and preserving food. We tested the device and found it can reach a vacuum level of 26 inches of mercury in an environment with an atmospheric pressure of 28.5 inches of mercury. We compared the performance of our vacuum device to a rotary-vane vacuum pump of ¼ horsepowers and found that the vacuum pump reaches a set test vacuum level of 25 inches of mercury before the compressor. We then demonstrated experimentally some features of the vacuum using the inverted compressor or the vane vacuum pump. These experiments se...
Wseas Transactions on Signal Processing, Oct 1, 2008
... 11. E. Gröschel, W. Schröder, P. Renze, M. Meinke, and P. Comte, Noise Prediction for a Turbu... more ... 11. E. Gröschel, W. Schröder, P. Renze, M. Meinke, and P. Comte, Noise Prediction for a Turbulent Jet Using Different Hybrid Methods ... 21. RR Mankbadi, SH Shih, R. Hixon, and LA Povinelli, Direct Computation of Jet Noise Produced by Large-Scale Axisymmetric Structures ...
We studied various characteristics of the flow-induced vibration (FIV) of a spring-mounted cylind... more We studied various characteristics of the flow-induced vibration (FIV) of a spring-mounted cylinder, and the fluctuating lift and drag forces exerted on the cylinder due to the periodic changes in the fluid motion and vortex structure. We compared two conditions, which represent the limiting cases for the solid-to-fluid density ratio: the cylinder density is negligible relative to the fluid density, and the fluid density is negligible relative to the cylinder density. For both conditions, we examined the changes in these characteristics over a wide range of nondimensional mass-damping for one degree of freedom (1-DOF, cross-flow) and 2-DOF (cross-flow and in-line) vibration. The four cases exhibit differences (especially at low mass-damping) but also have some similarities in the characteristics of the FIV, induced forces, and energy extraction from the flow. We examined these differences and similarities, the implied errors when the in-line DOF is neglected, and the feasibility of ...
We perform direct numerical simulations of the flow past a circular cylinder undergoing a one-deg... more We perform direct numerical simulations of the flow past a circular cylinder undergoing a one-degree-of-freedom transverse oscillation. The displacement follows a sine function raised to an arbitrary integer power ranging from 1 to 8. When the displacement power is above 2, we have multifrequency oscillation, and the number of Fourier components in the oscillation increases with the power, but they are either odd or even multiples of the input (argument) frequency of the displacement function. We study the responses of the nondimensional lift and drag under these different oscillation profiles and the transfer of nondimensional mechanical energy due to the oscillation, and their trends as the power (hence the number of Fourier components in the oscillation) increases. For odd powers, the energy is transferred to the cylinder; whereas for even powers, it is transferred to the flow. A unity power (harmonic oscillation) corresponds to the maximum energy transfer to the cylinder, which ...
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