Facilitator

Afrasyab Khan

Afrasyab Khan

Afrasyab Khan's Training:

I have served in National Development Complex (NDC), Pakistan which is a scientific organization for a period of more than 7 years where I have extensively worked on the projects which aimed to understand the physics of the flow related phenomena and on multi phase flow diagnostics. My objectives are always to put into practice the broader spectrum of Physics in engineering and on fluid flow related studies and especially to apply the state of the art instrumentation and diagnostic techniques for exploring the in depth realities of the physical phenomena prevailed for various multi phase fluids systems. I always wish to widen my understanding and knowledge regarding fluid mechanics, through my hard work in the novel research, however, also wish to develop novel techniques by using my knowledge. My research interests mainly are Multi phase Flows, Compressible Flows, Computational Fluid Dynamics, mechanical designing and manufacturing and Experimental Techniques in Fluid characterization.

Afrasyab Khan's Experience:

In the start I would like to introduce myself. My name is Dr. Afrasyab Khan and I have done PhD from University Malaysia Sarawak (UNIMAS) while on November 14, 2015 I have been graduated in a graceful ceremony of Post Graduate Convocation held in University Malaysia Sarawak. My research topic in PhD is related to the evaluation of the Hydrodynamic instabilities induced by supersonic steam jet. These instabilities have been created inside two or multiphase flow domains and till the date these instabilities have been investigated theoretically as well as experimentally in incompressible sonic flows. For the first time during the course of research on multiphase flows these instabilities have been investigated in supersonic flows in compressible fluids on experimental basis. The reason, that why these have not been investigated till the date is their transient and non-deterministic behavior. I investigate this facet of compressible flows by observing their generation inside supersonic steam and water interaction zone and I have observed that these hydrodynamic instabilities have been created at the interface between supersonic steam jet and subcooled water. Due to immense importance of the steam in multiphase domain my research findings grasp interest from the scientific community within no time and when I publish my findings, my first research paper titled as “Experimental Investigation of the Interface between Steam and Water Two Phase Flows” has been downloaded more than 700 times directly from Elsevier and around 142 times from the Research gate data base and earns a total of 8 citations if included the self-citations as well. The most important thing about the citing journals is that all of them are quartile one (Q1) journals which shows the immense valuable nature of these research findings. I apply LM 35 temperature sensors in my experiment which is a fast response digital precise temperature sensor. The commercial importance of these research findings can be access from this very fact that this research directly addresses the processes takes place in steam driven power industries and all the other process industries where steam can be used as a working fluid. These instabilities have been captured with the help of transient temperature fluctuations which have been captured experimentally with the help of LM35 temperature sensors and National Electronics Data Acquisition Card. These fluctuations have occurred transiently at a very short spatial length scale and then dissipated into the surrounding water. I have designed and manufacture a special vessel and measurement system which can be viewed from my first publication titled as “Experimental investigations of the interface between steam and water two phase flows” in International Journal of Heat and Mass Transfer, 73 (2014) 521–532. Followed by my second publication which is on the determination of the effectiveness of the hydrodynamic parameter for the attenuation of these instabilities (Determining potential of subcooling to attenuate hydrodynamic instabilities for steam–water two phase flow, International Journal of Heat and Mass Transfer, 84 (2015) 178–197). In which I quantitatively explain the more effectiveness of subcooling as compare to the steam inlet pressure on the attenuation of these hydrodynamic instabilities. I did not stop the quest of my research on the turbulent chaotic compressible and supersonic flows I also get a little change in the direction of my research where I work on these flow instabilities in terms of their physical properties and in this regard my findings have been accepted for publication in Asia-Pacific Journal of Chemical Engineering. I also use the state of the art P2000 ITOMS Electrical Resistance Tomography System (ERT) but the data and the scans that this system produced has given us very coarse images due to their inherent low processing time being online. I refined these images by using the data obtained from P2000 ERT system and process it with the help of “Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS)”. I use the EIDORS generated scans to calculate the void fraction of the supersonic steam jet inside subcooled water and my findings in this regard has been published in Journal of flow measurement and Instrumentation. To give a physical meaning to my research I move forward on my research on hydrodynamic instabilities by calculating the von-Mises Stresses and Total deformations caused by these instabilities on the confinements where the supersonic steam jet interact with subcooled water. I use the Fluid structure interaction (FSI) technique in Ansys Fluent along with the Direct Contact condensation (DCC) model to simulate the supersonic steam condensation and compute these stresses and deformation on theoretical basis. My findings in this regard are in final stage of review after minor corrections in Journal of Chemical Engineering Science. Few more of my research findings are in the stage of write up that include the effect of concurrent and counter current flows on the supersonic steam jet as well as the effect of gravity on compressible supersonic flows and thickness of the hot water layer around supersonic steam jet in which I will describe the use of the Electric Resistance Tomography (ERT) technique for the active area calculation across the supersonic steam jet. In the said paper I will calculate the approximate thickness of the hot water layer around the supersonic steam jet using ERT data based scans processed through EIDORS and image processing techniques as well as cross sections of the supersonic steam jet simulated results (obtained using DCC model in Ansys Fluent) in a vessel. The comparison of these two will yield valuable information related to the compressible supersonic reacting flows. In addition to it another facet of my research is the temporal life estimate of a supersonic steam bubble in subcooled water. I also plan to apply the stochastic modeling approaches to my data and reveal some predictable behavior of the hydrodynamic instabilities at varying hydrodynamic conditions. Till the date I have 8 publications with two more in line and according to my plans I can write 10 more papers on different aspects of hydrodynamic instabilities and on the diagnostic studies of these flows using the data that I already have.
Graduate Research (M.Sc Physics):
I did my B.Sc with Majors in Physics, Pure Mathematics & Applied Mathematics, followed by M.Sc (16 years of education) in Physics where our final year project was on the “Designing and manufacturing of the Laser eye based Land Leveler”. This project involved three photo diodes on which a laser beam has been aimed. Each of the photo diodes has been connected with the a light emitting diode so as soon as the incidence of the laser bean has been changed from the central diode, the electric siren beeps which indicated the person driving the agricultural farm tractor to adjust the level of the digger attached at the back of the agricultural farm tractor. This project helps the farmer a lot to save the irrigation water as according to a study it saves nearly 50% of the water that the farmers used to irrigate their whole land yet with the same yield. The electronics used in the said project is micro-controller based and we used 89C51 micro-controller to produce this automatic behavior.
Post Graduate Research (Master of Science):
In my taught MS (18 years of education) I studied the subjects mainly related with the Combustion, thrust & Propulsion. My research project was titled as “Modeling of heat and mass transfer in membrane of PEMFC fuel cell”. I use the equations of heat and mass transfer and then Spatio-temporally model the transport of water and ions inside the membrane of Polymer Electrolyte Membrane Fuel Cell (PEMFC).
Professional Experience:
I have served the National Development Complex (NDC) in Pakistan for more than seven years as Research Associate. The National Development Complex (NDC) is a defense and aerospace contractor and a division under the National Engineering and Science Commission (NESCOM), founded in 1990 at the Pakistan Ministry of Defense. The NDC is engaged in research and development in space-based missile systems and expanded its services towards developing the land-based weapons systems for the army as well as naval systems for the navy. During the tenure of my service I have worked on the diagnostic studies of high speed combustion driven flows in thrusters. I earned my experience related to the use of the invasive as well as non-invasive turbulence characterization techniques that is the Hot Wire Anemometry (HWA) and Laser Doppler Anemometry (LDA), while I have worked on the R&D related to the turbofan engines and thrusters.
My assignment was to measure the fluctuating velocity across the exit of the combustion chamber and its probability distribution using Gaussian probability density function. I use to measure the velocity in both cold and hot test scenarios. Along with this temperature have also been measured using thermos-couples. Along with velocity and temperature we were able to calculate the approximate thickness of the boundary layer, free stream velocity, shear, approximate momentum boundary layer, approximate thickness of the laminar sub-layer etc. all of these were calculated from the data obtained by using LDA in hot test conditions and HWA in cold test conditions. Along with it I have worked on the designing of the thrusters in which we not only investigate the effect of the dimensional variations on the thruster performance but also the effect of the change in reacting chemicals has been investigated. Like from Ru based catalyst to hydrazine based and then from the Nitrous oxide and Mono Methyl Hydrazine (MMH) or Unsymmetrical dimethyl-hydrazine (UDMH) fired thrusters, I worked in a group that did investigations of these lines to bring improvement in the thrust performance of the thrusters by reducing their size to make the Terminal Correction Systems (TCS) more light weight. We also measure the temperature at the thruster nozzle exit along with the pressure drop with the help of the thermo-couples and pressure transducers attached to the nozzle diverging section with the capillary opening.
Experimental Techniques Usage Experience:
Experimental Techniques that I can use include:
 Laser Doppler Anemometry (LDA)
 Hot Wire Anemometry (HWA)
 Electric Resistance Tomography (ERT)
 High Sample rate Temperature acquisition system (I have designed and manufacture it by my own during my PhD project)
 Pressure transducers
 High speed precision temperature sensors (LM35)
 High Speed (ICCD) Camera
Commercial and Open Source Codes Usage Experience:
I have used the following commercial and open source codes for the post processing of the Data:
 Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS) (I have used it to process the data obtained from ERT to get the RGB Scans. EIDORS is based on free software algorithms which give me more resolved RGB images)
 Origin Pro 7 (I have used it to draw the axial and radial temperature profiles based on the experimental data which I get from High Sample rate Temperature acquisition system)
 Matlab (I used it to draw the 3D contours as depicted from my two published research papers)
 Image processing (in it till now I was able to wrote a Matlab based program that gives me the %age of the number of pixels of each color in the RGB color scan that I have obtained by using ERT and then by post processing its data in EIDORS)
 Mathematica which I have been used during my Master of Science Degree project to model and simulate the transport of heat and mass transfer in membrane of PEMFC fuel cell.

Future Research:
My future plans are to characterize the high speed flows which prevailed mostly in industries that include aviation, process as well as power generation with non-invasive techniques like Laser Doppler Anemometry (LDA), PIV or fast response probes etc. By applying the modern diagnostic techniques on these fronts our understanding regarding the high speed flows and their effects like stresses or body forces on the accompanying systems in these configurations will get broader and our understanding regarding these scenarios will be much more improved. I also want to apply my imaginations on the designing and manufacturing of more sustainable systems that can be used for the energy production like wind power, where my basic aim is to address the issue of designing the wind turbines in the areas where the air circulation is not unidirectional. This on one side will help us to design more energy efficient systems and on the other side we will get an eye view into the physics involved in the wind based energy production systems. I am very passionate about my research on high speed turbulent flows and designing of more efficient energy systems. I want to diagnose these flows with modern techniques, and to explore the hidden physics behind them. But I am also a firm believer of this fact that we should not totally relay on the already established techniques to explore the hidden physics of these problems prevailed in the domain of fluid mechanics rather we should ponder on the new ways that are cheap, cost effective and more piercing. In addition to it I am a believer of the effectiveness of the cross field research where I could get an opportunity to work in a team where we have members from varied back grounds that collectively we explore the solutions of the day an age research problems prevailed in the domains of Physics in general and fluid mechanics as well as efficient energy systems in particular.

Afrasyab Khan's Experience with Online Groups:

In the start I would like to introduce myself. My name is Dr. Afrasyab Khan and I have done PhD from University Malaysia Sarawak (UNIMAS) while on November 14, 2015 I have been graduated in a graceful ceremony of Post Graduate Convocation held in University Malaysia Sarawak. My research topic in PhD is related to the evaluation of the Hydrodynamic instabilities induced by supersonic steam jet. These instabilities have been created inside two or multiphase flow domains and till the date these instabilities have been investigated theoretically as well as experimentally in incompressible sonic flows. For the first time during the course of research on multiphase flows these instabilities have been investigated in supersonic flows in compressible fluids on experimental basis. The reason, that why these have not been investigated till the date is their transient and non-deterministic behavior. I investigate this facet of compressible flows by observing their generation inside supersonic steam and water interaction zone and I have observed that these hydrodynamic instabilities have been created at the interface between supersonic steam jet and subcooled water. Due to immense importance of the steam in multiphase domain my research findings grasp interest from the scientific community within no time and when I publish my findings, my first research paper titled as “Experimental Investigation of the Interface between Steam and Water Two Phase Flows” has been downloaded more than 700 times directly from Elsevier and around 142 times from the Research gate data base and earns a total of 8 citations if included the self-citations as well. The most important thing about the citing journals is that all of them are quartile one (Q1) journals which shows the immense valuable nature of these research findings. I apply LM 35 temperature sensors in my experiment which is a fast response digital precise temperature sensor. The commercial importance of these research findings can be access from this very fact that this research directly addresses the processes takes place in steam driven power industries and all the other process industries where steam can be used as a working fluid. These instabilities have been captured with the help of transient temperature fluctuations which have been captured experimentally with the help of LM35 temperature sensors and National Electronics Data Acquisition Card. These fluctuations have occurred transiently at a very short spatial length scale and then dissipated into the surrounding water. I have designed and manufacture a special vessel and measurement system which can be viewed from my first publication titled as “Experimental investigations of the interface between steam and water two phase flows” in International Journal of Heat and Mass Transfer, 73 (2014) 521–532. Followed by my second publication which is on the determination of the effectiveness of the hydrodynamic parameter for the attenuation of these instabilities (Determining potential of subcooling to attenuate hydrodynamic instabilities for steam–water two phase flow, International Journal of Heat and Mass Transfer, 84 (2015) 178–197). In which I quantitatively explain the more effectiveness of subcooling as compare to the steam inlet pressure on the attenuation of these hydrodynamic instabilities. I did not stop the quest of my research on the turbulent chaotic compressible and supersonic flows I also get a little change in the direction of my research where I work on these flow instabilities in terms of their physical properties and in this regard my findings have been accepted for publication in Asia-Pacific Journal of Chemical Engineering. I also use the state of the art P2000 ITOMS Electrical Resistance Tomography System (ERT) but the data and the scans that this system produced has given us very coarse images due to their inherent low processing time being online. I refined these images by using the data obtained from P2000 ERT system and process it with the help of “Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS)”. I use the EIDORS generated scans to calculate the void fraction of the supersonic steam jet inside subcooled water and my findings in this regard has been published in Journal of flow measurement and Instrumentation. To give a physical meaning to my research I move forward on my research on hydrodynamic instabilities by calculating the von-Mises Stresses and Total deformations caused by these instabilities on the confinements where the supersonic steam jet interact with subcooled water. I use the Fluid structure interaction (FSI) technique in Ansys Fluent along with the Direct Contact condensation (DCC) model to simulate the supersonic steam condensation and compute these stresses and deformation on theoretical basis. My findings in this regard are in final stage of review after minor corrections in Journal of Chemical Engineering Science. Few more of my research findings are in the stage of write up that include the effect of concurrent and counter current flows on the supersonic steam jet as well as the effect of gravity on compressible supersonic flows and thickness of the hot water layer around supersonic steam jet in which I will describe the use of the Electric Resistance Tomography (ERT) technique for the active area calculation across the supersonic steam jet. In the said paper I will calculate the approximate thickness of the hot water layer around the supersonic steam jet using ERT data based scans processed through EIDORS and image processing techniques as well as cross sections of the supersonic steam jet simulated results (obtained using DCC model in Ansys Fluent) in a vessel. The comparison of these two will yield valuable information related to the compressible supersonic reacting flows. In addition to it another facet of my research is the temporal life estimate of a supersonic steam bubble in subcooled water. I also plan to apply the stochastic modeling approaches to my data and reveal some predictable behavior of the hydrodynamic instabilities at varying hydrodynamic conditions. Till the date I have 8 publications with two more in line and according to my plans I can write 10 more papers on different aspects of hydrodynamic instabilities and on the diagnostic studies of these flows using the data that I already have.
Graduate Research (M.Sc Physics):
I did my B.Sc with Majors in Physics, Pure Mathematics & Applied Mathematics, followed by M.Sc (16 years of education) in Physics where our final year project was on the “Designing and manufacturing of the Laser eye based Land Leveler”. This project involved three photo diodes on which a laser beam has been aimed. Each of the photo diodes has been connected with the a light emitting diode so as soon as the incidence of the laser bean has been changed from the central diode, the electric siren beeps which indicated the person driving the agricultural farm tractor to adjust the level of the digger attached at the back of the agricultural farm tractor. This project helps the farmer a lot to save the irrigation water as according to a study it saves nearly 50% of the water that the farmers used to irrigate their whole land yet with the same yield. The electronics used in the said project is micro-controller based and we used 89C51 micro-controller to produce this automatic behavior.
Post Graduate Research (Master of Science):
In my taught MS (18 years of education) I studied the subjects mainly related with the Combustion, thrust & Propulsion. My research project was titled as “Modeling of heat and mass transfer in membrane of PEMFC fuel cell”. I use the equations of heat and mass transfer and then Spatio-temporally model the transport of water and ions inside the membrane of Polymer Electrolyte Membrane Fuel Cell (PEMFC).
Professional Experience:
I have served the National Development Complex (NDC) in Pakistan for more than seven years as Research Associate. The National Development Complex (NDC) is a defense and aerospace contractor and a division under the National Engineering and Science Commission (NESCOM), founded in 1990 at the Pakistan Ministry of Defense. The NDC is engaged in research and development in space-based missile systems and expanded its services towards developing the land-based weapons systems for the army as well as naval systems for the navy. During the tenure of my service I have worked on the diagnostic studies of high speed combustion driven flows in thrusters. I earned my experience related to the use of the invasive as well as non-invasive turbulence characterization techniques that is the Hot Wire Anemometry (HWA) and Laser Doppler Anemometry (LDA), while I have worked on the R&D related to the turbofan engines and thrusters.
My assignment was to measure the fluctuating velocity across the exit of the combustion chamber and its probability distribution using Gaussian probability density function. I use to measure the velocity in both cold and hot test scenarios. Along with this temperature have also been measured using thermos-couples. Along with velocity and temperature we were able to calculate the approximate thickness of the boundary layer, free stream velocity, shear, approximate momentum boundary layer, approximate thickness of the laminar sub-layer etc. all of these were calculated from the data obtained by using LDA in hot test conditions and HWA in cold test conditions. Along with it I have worked on the designing of the thrusters in which we not only investigate the effect of the dimensional variations on the thruster performance but also the effect of the change in reacting chemicals has been investigated. Like from Ru based catalyst to hydrazine based and then from the Nitrous oxide and Mono Methyl Hydrazine (MMH) or Unsymmetrical dimethyl-hydrazine (UDMH) fired thrusters, I worked in a group that did investigations of these lines to bring improvement in the thrust performance of the thrusters by reducing their size to make the Terminal Correction Systems (TCS) more light weight. We also measure the temperature at the thruster nozzle exit along with the pressure drop with the help of the thermo-couples and pressure transducers attached to the nozzle diverging section with the capillary opening.
Experimental Techniques Usage Experience:
Experimental Techniques that I can use include:
 Laser Doppler Anemometry (LDA)
 Hot Wire Anemometry (HWA)
 Electric Resistance Tomography (ERT)
 High Sample rate Temperature acquisition system (I have designed and manufacture it by my own during my PhD project)
 Pressure transducers
 High speed precision temperature sensors (LM35)
 High Speed (ICCD) Camera
Commercial and Open Source Codes Usage Experience:
I have used the following commercial and open source codes for the post processing of the Data:
 Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS) (I have used it to process the data obtained from ERT to get the RGB Scans. EIDORS is based on free software algorithms which give me more resolved RGB images)
 Origin Pro 7 (I have used it to draw the axial and radial temperature profiles based on the experimental data which I get from High Sample rate Temperature acquisition system)
 Matlab (I used it to draw the 3D contours as depicted from my two published research papers)
 Image processing (in it till now I was able to wrote a Matlab based program that gives me the %age of the number of pixels of each color in the RGB color scan that I have obtained by using ERT and then by post processing its data in EIDORS)
 Mathematica which I have been used during my Master of Science Degree project to model and simulate the transport of heat and mass transfer in membrane of PEMFC fuel cell.

Future Research:
My future plans are to characterize the high speed flows which prevailed mostly in industries that include aviation, process as well as power generation with non-invasive techniques like Laser Doppler Anemometry (LDA), PIV or fast response probes etc. By applying the modern diagnostic techniques on these fronts our understanding regarding the high speed flows and their effects like stresses or body forces on the accompanying systems in these configurations will get broader and our understanding regarding these scenarios will be much more improved. I also want to apply my imaginations on the designing and manufacturing of more sustainable systems that can be used for the energy production like wind power, where my basic aim is to address the issue of designing the wind turbines in the areas where the air circulation is not unidirectional. This on one side will help us to design more energy efficient systems and on the other side we will get an eye view into the physics involved in the wind based energy production systems. I am very passionate about my research on high speed turbulent flows and designing of more efficient energy systems. I want to diagnose these flows with modern techniques, and to explore the hidden physics behind them. But I am also a firm believer of this fact that we should not totally relay on the already established techniques to explore the hidden physics of these problems prevailed in the domain of fluid mechanics rather we should ponder on the new ways that are cheap, cost effective and more piercing. In addition to it I am a believer of the effectiveness of the cross field research where I could get an opportunity to work in a team where we have members from varied back grounds that collectively we explore the solutions of the day an age research problems prevailed in the domains of Physics in general and fluid mechanics as well as efficient energy systems in particular.