Carlos Lange | University of Alberta (original) (raw)

Papers by Carlos Lange

Bulletin of the American Physical Society, Nov 25, 2014

A wide range of trailers with very poor aerodynamics are hauled long distances across a vast Nort... more A wide range of trailers with very poor aerodynamics are hauled long distances across a vast North American highway system. Our goal was to use preliminary smoke-wire flow visualizations to learn: the characteristic flow patterns over models representing modern Vehicle-Trailer Systems (VTS); what improvements need to be made in the experimental setup ; and if there is an opportunity for reduction in aerodynamic drag. Visualization tests were done in an open circuit wind tunnel, with a cross-sectional area of 0.3 m 2. Detailed models of light duty trucks and trailers were used at a Reynolds number of 13,700. Images of the streaklines indicated two characteristic features. One was the presence of a stagnation point on the leading face of the trailer followed by a separation bubble on its top. The other feature was an unexpected separation bubble on the hood of the towing vehicle. We determined that it did not have a significant effect on the downstream flow pattern. By adding a small wedge deflector on the cab of the vehicle it was concluded that there is an opportunity for significant improvement of the VTS aerodynamics. Computational simulation of the flow is underway.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights • The in-house UnSteady Double Wake Model USDWM is presented in the manuscript. • Sub-, super-, and trans-critical cylinder flows have been successfully simulated. • The results show a good comparison between USDWM, URANS, and experiments. • USDWM is capable of capturing the dynamics of the flow. • USDWM is capable of capturing changes in St, Cd and Cp for the three regimes.

41st Annual Lunar and Planetary Science Conference, Mar 1, 2010

In this contribution we discuss two different origins of dust activity at the Mars Phoenix landin... more In this contribution we discuss two different origins of dust activity at the Mars Phoenix landing site using lander data and images taken of the North Polar region on Mars by the Mars Color Imager onboard Mars Reconnaissance Orbiter.

AGUFM, Dec 1, 2008

Abstract The Phoenix mission has included several instruments for observing the atmosphere of Mar... more Abstract The Phoenix mission has included several instruments for observing the atmosphere of Mars. The measurements include atmospheric temperature, pressure, wind, humidity, optical depth, composition, and imaging. A unique instrument on the Phoenix ...

AGU Fall Meeting Abstracts, Dec 1, 2008

Wind speeds and directions were measured on the Phoenix Lander by a mechanical anemometer, the so... more Wind speeds and directions were measured on the Phoenix Lander by a mechanical anemometer, the so-called Telltale wind indicator. Analysis of images of the instrument taken with the onboard imager allowed for evaluation of wind speeds and directions. Daily characteristics of the wind data are highly turbulent behavior during midday due to daytime turbulence with more stable conditions during nighttime. From L s ∼77°-123°winds were generally ∼4 m s −1 from the east, with 360°rotation during midday. From L s ∼123°-148°d aytime wind speeds increased to an average of 6-10 m s −1 and were generally from the west. The highest wind speed recorded was 16 m s −1 seen on L s ∼147°. Estimates of the surface roughness height are calculated from the smearing of the Kapton part of the Telltale during image exposure due to a 3 Hz turbulence and nighttime wind variability. These estimates yield 6 ± 3 mm and 5 ± 3 mm, respectively. The Telltale wind data are used to suggest that Heimdal crater is a source of nighttime temperature fluctuations. Deviations between temperatures measured at various heights are explained as being due to winds passing over the Phoenix Lander. Events concerning sample delivery and frost formation are described and discussed. Two different mechanisms of dust lifting affecting the Phoenix site are proposed based on observations made with Mars Color Imager on Mars Reconnaissance Orbiter and the Telltale. The first is related to evaporation of the seasonal CO 2 ice and is observed up to L s ∼95°. These events are not associated with increased wind speeds. The second mechanism is observed after L s ∼111°and is related to the passing of weather systems characterized by condensate clouds in orbital images and higher wind speeds as measured with the Telltale.

Advanced Engineering Informatics

Progress in Canadian Mechanical Engineering. Volume 4, 2021

A BSTRACT A transient thermal circuit model was developed by the AlbertaSat Student Team for the ... more A BSTRACT A transient thermal circuit model was developed by the AlbertaSat Student Team for the Northern SPIRIT cube satellites: Ex-Alta 2 (3U), YukonSat (2U) and AuroraSat (2U), which are to be launched into Low Earth Orbit. The model was used to study heat transfer and determine temperature profiles over time in each CubeSat. The thermal resistance analogy for conductive heat transfer was utilized, assuming convection as negligible under vacuum conditions.

SPE Kuwait Oil & Gas Show and Conference, 2019

Flashing flow is a common phenomenon in many industrial applications and, in steam-assisted gravi... more Flashing flow is a common phenomenon in many industrial applications and, in steam-assisted gravity drainage (SAGD), it is considered a significant process. Flashing may occur if there is a sudden pressure drop in the production well in SAGD, which is a typical in-situ way to extract heavy oil from tar sands. This may change the expected pressure drop across inflow control devices (ICDs), which are the controllers installed within the production well. Flashing is defined as self-boiling of a liquid due to a reduction of pressure, and it is a complex, multiphase flow phenomenon. The main objectives of the present work are to develop and to validate a multiphase computational model that has the ability to predict the thermo-fluid behaviour of the flow during the flashing process inside ICD nozzles, and to assess its effect on the pressure distribution through ICDs in a predictive way. Our computational model is applied to time-averaged, two-phase, adiabatic, turbulent flows. The new c...

Day 1 Mon, December 10, 2018, 2018

Several parameters affect the skin factor of the cased and perforated (C&P) wells completed with ... more Several parameters affect the skin factor of the cased and perforated (C&P) wells completed with slotted liners. Existing skin factor models for slotted liners account for such factors as the flow convergence, pressure drop and partial production but neglect phenomena such as partial plugging of the screen or near-wellbore permeability alterations during the production. This paper discusses these factors and incorporates them into a skin model using a finite volume simulation. The finite volume analysis evaluates the skin factor as a result of pressure drop in the gap between the casing wall and the slotted liner. This skin model accounts for: 1) the perforation density and phasing, 2) slotted liner specifications, and 3) different amount of sand accumulation in the annular space between the casing and the sand screen. A semi-analytical pressure drop model is also linked to the numerical model to incorporate the skin factor due to flow convergence behind the perforations. The result...

MetNet Mars Mission is an in situ observational network and orbital platform mission to investiga... more MetNet Mars Mission is an in situ observational network and orbital platform mission to investigate the Martian environment and it has been proposed to European Space Agency in response to Call for proposals for the first planning cycle of Cosmic Vision 2015-2025 D/SCI/DJS/SV/val/21851. The MetNet Mars Mission is to be implemented in collaboration with ESA, FMI, LA, IKI and the payload providing science teams. The scope of the MetNet Mission is to deploy 16 MetNet Landers (MNLs) on the Martian surface by using inflatable descent system structures accompanied by an atmospheric sounder and data relay onboard the MetNet Orbiter (MNO), which is based on ESA Mars Express satellite platform. The MNLs are attached on the three sides of the satellite and most of the MNLs are deployed to Mars separately a few weeks prior to the arrival to Mars. The MetNet Orbiter will perform continuous atmospheric soundings thus complementing the accurate in situ observations at the Martian ground produced by the MetNet observation network, as well as the orbiter will serve as the primary data relay between the MetNet Landers and the Earth. The MNLs are equipped with a versatile science payload focused on the atmospheric science of Mars. Detailed characterisation of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatological cycles, as well as interior investigations, require simultaneous in-situ meteorological, seismic and magnetic measurements from networks of stations on the Martian surface. MetNet Mars Mission will also provide a crucial support for the safety of large landing missions in general and manned Mars missions in particular. Accurate knowledge of atmospheric conditions and weather data is essential to guarantee safe landings of the forthcoming Mars mission elements.

AGUFM, Dec 1, 2008

During the Phoenix lander mission air temperatures were measured at three levels on a 1-m mast an... more During the Phoenix lander mission air temperatures were measured at three levels on a 1-m mast and pressure was measured on the deck of the lander, itself about 1 m above ground level. Measurements were made at 0.5 Hz and has run almost continuously through the landed mission apart from short daily breaks for data transfers. The diurnal temperature data

67th Annual Meeting of the APS Division of Fluid Dynamics - Gallery of Fluid Motion, 2014

Energies

This research presents a validation methodology for computational fluid dynamics (CFD) assessment... more This research presents a validation methodology for computational fluid dynamics (CFD) assessments of rooftop wind regime in urban environments. A case study is carried out at the Donadeo Innovation Centre for Engineering building at the University of Alberta campus. A numerical assessment of rooftop wind regime around buildings of the University of Alberta North campus has been performed by using 3D steady Reynolds-averaged Navier–Stokes equations, on a large-scale high-resolution grid using the ANSYS CFX code. Two methods of standard deviation (SDM) and average (AM) were introduced to compare the numerical results with the corresponding measurements. The standard deviation method showed slightly better agreements between the numerical results and measurements compared to the average method, by showing the average wind speed errors of 10.8% and 17.7%, and wind direction deviation of 8.4° and 12.3°, for incident winds from East and South, respectively. However, the average error bet...

Atmosphere

Computational Fluid Dynamics (CFD) is used to accurately model and predict the dispersion of a pa... more Computational Fluid Dynamics (CFD) is used to accurately model and predict the dispersion of a passive scalar in the atmospheric wind flow field within an urban setting. The Mock Urban Setting Tests (MUST) experiment was recreated in this work to test and evaluate various modeling settings and to form a framework for reliable representation of dispersion flow in compact urban geometries. Four case studies with distinct source locations and configurations are modeled using Reynolds-Averaged Navier–Stokes (RANS) equations with ANSYS CFX. The performance of three widely suggested closure models of standard k−ε, RNG k−ε, and SST k−ω is assessed by calculating and interpreting the statistical performance metrics with a specific emphasis on the effects of the source locations. This work demonstrates that the overprediction of the turbulent kinetic energy by the standard k−ε counteracts the general underpredictions by RANS in geometries with building complexes. As a result, the superiority...

Micromachines, 2022

Based on expert system theory and fluid–structure interaction (FSI), this paper suggests an intel... more Based on expert system theory and fluid–structure interaction (FSI), this paper suggests an intelligent design optimization system to derive the optimal shape of both the fluid and solid domain of flow channels. A parametric modeling scheme of flow channels is developed by design for additive manufacturing (DfAM). By changing design parameters, a series of flow channel models can be obtained. According to the design characteristics, the system can intelligently allocate suitable computational models to compute the flow field of a specific model. The pressure-based normal stress is abstracted from the results and transmitted to the solid region by the fluid–structure (FS) interface to analyze the strength of the structure. The design space is obtained by investigating the simulation results with the metamodeling method, which is further applied for pursuing design objectives under constraints. Finally, the improved design is derived by gradient-based optimization. This system can imp...

A compact imaging payload consisting of visible-near infrared and short-wave infrared capability ... more A compact imaging payload consisting of visible-near infrared and short-wave infrared capability is being developed to demonstrate low-cost wildfire monitoring among other Earth observations. Iris is a 1U multispectral push-broom imager that is capable of generating spectral data pertinent for wildfire science and wildfire risk analysis from a CubeSat platform. This payload is slated to fly on-board Ex-Alta 2, the University of Alberta’s second CubeSat and Alberta’s contribution to the Canadian CubeSat Project, to be deployed from the International Space Station in 2022. Iris features four closely integrated designs: optical, structural, electronics, and firmware. The mechanical and electronic interfaces of Iris are suited for modular integration into 1U of other generic CubeSat structures. The design has significant constraints on mass, size, performance, and cost. The current optical design features two compact lightpaths within the housing for imaging in short-wave infrared, near...

A computational study of the flow past a circular cylinder at low Reynolds number is performed. A... more A computational study of the flow past a circular cylinder at low Reynolds number is performed. At this Reynolds number Von Karman vortex shedding wake is observed. To attenuate this wake two actuators that inject fluid or remove fluid from the surface of the cylinder are used. The investigation is performed numerically by solving the Navier-Stokes equations in two-dimensions using OpenFOAM which is an open source code. The code is first validated without actuation on results from the literature for Von Karman vortex shedding at low Reynolds number and then used to study active (open loop) control of vortex shedding to reduce drag and control the vortex strength.

To prepare for the simulation of sand filtration in heavy oil, the detailed flow of individual pa... more To prepare for the simulation of sand filtration in heavy oil, the detailed flow of individual particles in oil is studied. Investigation of the motion of a bouncing solid particle toward the wall in a fluid helps understand the particle-fluid and particlewall interactions in the numerical model. The numerical results get verified against experimental data through reporting Root Mean Square Error (RMSE). The particle distance-from-wall is measured. Although some numerical research has been carried out on spherical bouncing particle, there have been few numerical investigations into the effect of the non-spherical particles on the trajectory/distance-from-wall of the falling/bouncing particle toward the wall in a fluid. Accordingly, the specific aims of this work are: 1) Checking that the developed numerical model can simulate the motion of a bouncing spherical particle. It will result in validating/benchmarking the developed model from the perspective of particle-wall and particle-fluid interactions. 2) Comparative study on the effect of the solid particle spherical shape and polyhedral shape on the trajectory/distance-from-wall of the particle. Considering the quiescent fluid of silicon oil in a tank made of glass, a steel sphere is falling in oil toward the bottom glass wall. The mass density of the steel sphere is ρp = 7800 kg/m 3. The Young's modulus of elasticity E is 214 × 109 Pa and the Poisson's ratio v is 0.3. The mass density of silicon oil is ρf = 970 kg/m 3 and the dynamic viscosity is µ = 0.1 Pa.s (at T = 20° C). Size of the steel sphere, Re and St numbers are 0.0053 m, 30 and 55, respectively. The trajectory/distance-from-wall of the particle is affected by particle-fluid and particle-wall interactions. The particle trajectory/distance-from-wall and the interactions with fluid and wall will be investigated numerically in STAR-CCM+ using Coupled Computational Fluid Dynamics and Discrete Element Method (CFD-DEM). DEM simulations are capable of tracking individual particles' trajectories, considering various forces on the particles caused by interaction with fluid, with other particles, and with walls. Also, STARCCM+ can simulate non-spherical particles. This work shows that the developed model predicts the trajectory/distance-from-wall of the bouncing spherical particle with a RSME equal or less than 0.1. Also, the trajectory/distance-from-wall of the polyhedral particle differs from the spherical particles, demonstrating that shape matters. Changes in the drag force due to changes in particle shape will be also investigated. Further work will apply the model findings to the study of particle filtration.

Bulletin of the American Physical Society, Nov 25, 2014

A wide range of trailers with very poor aerodynamics are hauled long distances across a vast Nort... more A wide range of trailers with very poor aerodynamics are hauled long distances across a vast North American highway system. Our goal was to use preliminary smoke-wire flow visualizations to learn: the characteristic flow patterns over models representing modern Vehicle-Trailer Systems (VTS); what improvements need to be made in the experimental setup ; and if there is an opportunity for reduction in aerodynamic drag. Visualization tests were done in an open circuit wind tunnel, with a cross-sectional area of 0.3 m 2. Detailed models of light duty trucks and trailers were used at a Reynolds number of 13,700. Images of the streaklines indicated two characteristic features. One was the presence of a stagnation point on the leading face of the trailer followed by a separation bubble on its top. The other feature was an unexpected separation bubble on the hood of the towing vehicle. We determined that it did not have a significant effect on the downstream flow pattern. By adding a small wedge deflector on the cab of the vehicle it was concluded that there is an opportunity for significant improvement of the VTS aerodynamics. Computational simulation of the flow is underway.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights • The in-house UnSteady Double Wake Model USDWM is presented in the manuscript. • Sub-, super-, and trans-critical cylinder flows have been successfully simulated. • The results show a good comparison between USDWM, URANS, and experiments. • USDWM is capable of capturing the dynamics of the flow. • USDWM is capable of capturing changes in St, Cd and Cp for the three regimes.

41st Annual Lunar and Planetary Science Conference, Mar 1, 2010

In this contribution we discuss two different origins of dust activity at the Mars Phoenix landin... more In this contribution we discuss two different origins of dust activity at the Mars Phoenix landing site using lander data and images taken of the North Polar region on Mars by the Mars Color Imager onboard Mars Reconnaissance Orbiter.

AGUFM, Dec 1, 2008

Abstract The Phoenix mission has included several instruments for observing the atmosphere of Mar... more Abstract The Phoenix mission has included several instruments for observing the atmosphere of Mars. The measurements include atmospheric temperature, pressure, wind, humidity, optical depth, composition, and imaging. A unique instrument on the Phoenix ...

AGU Fall Meeting Abstracts, Dec 1, 2008

Wind speeds and directions were measured on the Phoenix Lander by a mechanical anemometer, the so... more Wind speeds and directions were measured on the Phoenix Lander by a mechanical anemometer, the so-called Telltale wind indicator. Analysis of images of the instrument taken with the onboard imager allowed for evaluation of wind speeds and directions. Daily characteristics of the wind data are highly turbulent behavior during midday due to daytime turbulence with more stable conditions during nighttime. From L s ∼77°-123°winds were generally ∼4 m s −1 from the east, with 360°rotation during midday. From L s ∼123°-148°d aytime wind speeds increased to an average of 6-10 m s −1 and were generally from the west. The highest wind speed recorded was 16 m s −1 seen on L s ∼147°. Estimates of the surface roughness height are calculated from the smearing of the Kapton part of the Telltale during image exposure due to a 3 Hz turbulence and nighttime wind variability. These estimates yield 6 ± 3 mm and 5 ± 3 mm, respectively. The Telltale wind data are used to suggest that Heimdal crater is a source of nighttime temperature fluctuations. Deviations between temperatures measured at various heights are explained as being due to winds passing over the Phoenix Lander. Events concerning sample delivery and frost formation are described and discussed. Two different mechanisms of dust lifting affecting the Phoenix site are proposed based on observations made with Mars Color Imager on Mars Reconnaissance Orbiter and the Telltale. The first is related to evaporation of the seasonal CO 2 ice and is observed up to L s ∼95°. These events are not associated with increased wind speeds. The second mechanism is observed after L s ∼111°and is related to the passing of weather systems characterized by condensate clouds in orbital images and higher wind speeds as measured with the Telltale.

Advanced Engineering Informatics

Progress in Canadian Mechanical Engineering. Volume 4, 2021

A BSTRACT A transient thermal circuit model was developed by the AlbertaSat Student Team for the ... more A BSTRACT A transient thermal circuit model was developed by the AlbertaSat Student Team for the Northern SPIRIT cube satellites: Ex-Alta 2 (3U), YukonSat (2U) and AuroraSat (2U), which are to be launched into Low Earth Orbit. The model was used to study heat transfer and determine temperature profiles over time in each CubeSat. The thermal resistance analogy for conductive heat transfer was utilized, assuming convection as negligible under vacuum conditions.

SPE Kuwait Oil & Gas Show and Conference, 2019

Flashing flow is a common phenomenon in many industrial applications and, in steam-assisted gravi... more Flashing flow is a common phenomenon in many industrial applications and, in steam-assisted gravity drainage (SAGD), it is considered a significant process. Flashing may occur if there is a sudden pressure drop in the production well in SAGD, which is a typical in-situ way to extract heavy oil from tar sands. This may change the expected pressure drop across inflow control devices (ICDs), which are the controllers installed within the production well. Flashing is defined as self-boiling of a liquid due to a reduction of pressure, and it is a complex, multiphase flow phenomenon. The main objectives of the present work are to develop and to validate a multiphase computational model that has the ability to predict the thermo-fluid behaviour of the flow during the flashing process inside ICD nozzles, and to assess its effect on the pressure distribution through ICDs in a predictive way. Our computational model is applied to time-averaged, two-phase, adiabatic, turbulent flows. The new c...

Day 1 Mon, December 10, 2018, 2018

Several parameters affect the skin factor of the cased and perforated (C&P) wells completed with ... more Several parameters affect the skin factor of the cased and perforated (C&P) wells completed with slotted liners. Existing skin factor models for slotted liners account for such factors as the flow convergence, pressure drop and partial production but neglect phenomena such as partial plugging of the screen or near-wellbore permeability alterations during the production. This paper discusses these factors and incorporates them into a skin model using a finite volume simulation. The finite volume analysis evaluates the skin factor as a result of pressure drop in the gap between the casing wall and the slotted liner. This skin model accounts for: 1) the perforation density and phasing, 2) slotted liner specifications, and 3) different amount of sand accumulation in the annular space between the casing and the sand screen. A semi-analytical pressure drop model is also linked to the numerical model to incorporate the skin factor due to flow convergence behind the perforations. The result...

MetNet Mars Mission is an in situ observational network and orbital platform mission to investiga... more MetNet Mars Mission is an in situ observational network and orbital platform mission to investigate the Martian environment and it has been proposed to European Space Agency in response to Call for proposals for the first planning cycle of Cosmic Vision 2015-2025 D/SCI/DJS/SV/val/21851. The MetNet Mars Mission is to be implemented in collaboration with ESA, FMI, LA, IKI and the payload providing science teams. The scope of the MetNet Mission is to deploy 16 MetNet Landers (MNLs) on the Martian surface by using inflatable descent system structures accompanied by an atmospheric sounder and data relay onboard the MetNet Orbiter (MNO), which is based on ESA Mars Express satellite platform. The MNLs are attached on the three sides of the satellite and most of the MNLs are deployed to Mars separately a few weeks prior to the arrival to Mars. The MetNet Orbiter will perform continuous atmospheric soundings thus complementing the accurate in situ observations at the Martian ground produced by the MetNet observation network, as well as the orbiter will serve as the primary data relay between the MetNet Landers and the Earth. The MNLs are equipped with a versatile science payload focused on the atmospheric science of Mars. Detailed characterisation of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatological cycles, as well as interior investigations, require simultaneous in-situ meteorological, seismic and magnetic measurements from networks of stations on the Martian surface. MetNet Mars Mission will also provide a crucial support for the safety of large landing missions in general and manned Mars missions in particular. Accurate knowledge of atmospheric conditions and weather data is essential to guarantee safe landings of the forthcoming Mars mission elements.

AGUFM, Dec 1, 2008

During the Phoenix lander mission air temperatures were measured at three levels on a 1-m mast an... more During the Phoenix lander mission air temperatures were measured at three levels on a 1-m mast and pressure was measured on the deck of the lander, itself about 1 m above ground level. Measurements were made at 0.5 Hz and has run almost continuously through the landed mission apart from short daily breaks for data transfers. The diurnal temperature data

67th Annual Meeting of the APS Division of Fluid Dynamics - Gallery of Fluid Motion, 2014

Energies

This research presents a validation methodology for computational fluid dynamics (CFD) assessment... more This research presents a validation methodology for computational fluid dynamics (CFD) assessments of rooftop wind regime in urban environments. A case study is carried out at the Donadeo Innovation Centre for Engineering building at the University of Alberta campus. A numerical assessment of rooftop wind regime around buildings of the University of Alberta North campus has been performed by using 3D steady Reynolds-averaged Navier–Stokes equations, on a large-scale high-resolution grid using the ANSYS CFX code. Two methods of standard deviation (SDM) and average (AM) were introduced to compare the numerical results with the corresponding measurements. The standard deviation method showed slightly better agreements between the numerical results and measurements compared to the average method, by showing the average wind speed errors of 10.8% and 17.7%, and wind direction deviation of 8.4° and 12.3°, for incident winds from East and South, respectively. However, the average error bet...

Atmosphere

Computational Fluid Dynamics (CFD) is used to accurately model and predict the dispersion of a pa... more Computational Fluid Dynamics (CFD) is used to accurately model and predict the dispersion of a passive scalar in the atmospheric wind flow field within an urban setting. The Mock Urban Setting Tests (MUST) experiment was recreated in this work to test and evaluate various modeling settings and to form a framework for reliable representation of dispersion flow in compact urban geometries. Four case studies with distinct source locations and configurations are modeled using Reynolds-Averaged Navier–Stokes (RANS) equations with ANSYS CFX. The performance of three widely suggested closure models of standard k−ε, RNG k−ε, and SST k−ω is assessed by calculating and interpreting the statistical performance metrics with a specific emphasis on the effects of the source locations. This work demonstrates that the overprediction of the turbulent kinetic energy by the standard k−ε counteracts the general underpredictions by RANS in geometries with building complexes. As a result, the superiority...

Micromachines, 2022

Based on expert system theory and fluid–structure interaction (FSI), this paper suggests an intel... more Based on expert system theory and fluid–structure interaction (FSI), this paper suggests an intelligent design optimization system to derive the optimal shape of both the fluid and solid domain of flow channels. A parametric modeling scheme of flow channels is developed by design for additive manufacturing (DfAM). By changing design parameters, a series of flow channel models can be obtained. According to the design characteristics, the system can intelligently allocate suitable computational models to compute the flow field of a specific model. The pressure-based normal stress is abstracted from the results and transmitted to the solid region by the fluid–structure (FS) interface to analyze the strength of the structure. The design space is obtained by investigating the simulation results with the metamodeling method, which is further applied for pursuing design objectives under constraints. Finally, the improved design is derived by gradient-based optimization. This system can imp...

A compact imaging payload consisting of visible-near infrared and short-wave infrared capability ... more A compact imaging payload consisting of visible-near infrared and short-wave infrared capability is being developed to demonstrate low-cost wildfire monitoring among other Earth observations. Iris is a 1U multispectral push-broom imager that is capable of generating spectral data pertinent for wildfire science and wildfire risk analysis from a CubeSat platform. This payload is slated to fly on-board Ex-Alta 2, the University of Alberta’s second CubeSat and Alberta’s contribution to the Canadian CubeSat Project, to be deployed from the International Space Station in 2022. Iris features four closely integrated designs: optical, structural, electronics, and firmware. The mechanical and electronic interfaces of Iris are suited for modular integration into 1U of other generic CubeSat structures. The design has significant constraints on mass, size, performance, and cost. The current optical design features two compact lightpaths within the housing for imaging in short-wave infrared, near...

A computational study of the flow past a circular cylinder at low Reynolds number is performed. A... more A computational study of the flow past a circular cylinder at low Reynolds number is performed. At this Reynolds number Von Karman vortex shedding wake is observed. To attenuate this wake two actuators that inject fluid or remove fluid from the surface of the cylinder are used. The investigation is performed numerically by solving the Navier-Stokes equations in two-dimensions using OpenFOAM which is an open source code. The code is first validated without actuation on results from the literature for Von Karman vortex shedding at low Reynolds number and then used to study active (open loop) control of vortex shedding to reduce drag and control the vortex strength.

To prepare for the simulation of sand filtration in heavy oil, the detailed flow of individual pa... more To prepare for the simulation of sand filtration in heavy oil, the detailed flow of individual particles in oil is studied. Investigation of the motion of a bouncing solid particle toward the wall in a fluid helps understand the particle-fluid and particlewall interactions in the numerical model. The numerical results get verified against experimental data through reporting Root Mean Square Error (RMSE). The particle distance-from-wall is measured. Although some numerical research has been carried out on spherical bouncing particle, there have been few numerical investigations into the effect of the non-spherical particles on the trajectory/distance-from-wall of the falling/bouncing particle toward the wall in a fluid. Accordingly, the specific aims of this work are: 1) Checking that the developed numerical model can simulate the motion of a bouncing spherical particle. It will result in validating/benchmarking the developed model from the perspective of particle-wall and particle-fluid interactions. 2) Comparative study on the effect of the solid particle spherical shape and polyhedral shape on the trajectory/distance-from-wall of the particle. Considering the quiescent fluid of silicon oil in a tank made of glass, a steel sphere is falling in oil toward the bottom glass wall. The mass density of the steel sphere is ρp = 7800 kg/m 3. The Young's modulus of elasticity E is 214 × 109 Pa and the Poisson's ratio v is 0.3. The mass density of silicon oil is ρf = 970 kg/m 3 and the dynamic viscosity is µ = 0.1 Pa.s (at T = 20° C). Size of the steel sphere, Re and St numbers are 0.0053 m, 30 and 55, respectively. The trajectory/distance-from-wall of the particle is affected by particle-fluid and particle-wall interactions. The particle trajectory/distance-from-wall and the interactions with fluid and wall will be investigated numerically in STAR-CCM+ using Coupled Computational Fluid Dynamics and Discrete Element Method (CFD-DEM). DEM simulations are capable of tracking individual particles' trajectories, considering various forces on the particles caused by interaction with fluid, with other particles, and with walls. Also, STARCCM+ can simulate non-spherical particles. This work shows that the developed model predicts the trajectory/distance-from-wall of the bouncing spherical particle with a RSME equal or less than 0.1. Also, the trajectory/distance-from-wall of the polyhedral particle differs from the spherical particles, demonstrating that shape matters. Changes in the drag force due to changes in particle shape will be also investigated. Further work will apply the model findings to the study of particle filtration.