Sergiu P Iliev | Imperial College London (original) (raw)

Papers by Sergiu P Iliev

Journal of Space Weather and Space Climate, 2015

An accurate forecast of flare and coronal mass ejection (CME) initiation requires precise measure... more An accurate forecast of flare and coronal mass ejection (CME) initiation requires precise measurements of the magnetic energy buildup and release in the active regions of the solar atmosphere. We designed a new space weather mission that performs such measurements using new optical instruments based on the Hanle and Zeeman effects. The mission consists of two satellites, one orbiting the L1 Lagrangian point (Spacecraft Earth, SCE) and the second in heliocentric orbit at 1AU trailing the Earth by 80°(Spacecraft 80, SC80). Optical instruments measure the vector magnetic field in multiple layers of the solar atmosphere. The orbits of the spacecraft allow for a continuous imaging of nearly 73% of the total solar surface. In-situ plasma instruments detect solar wind conditions at 1AU and ahead of our planet. Earth-directed CMEs can be tracked using the stereoscopic view of the spacecraft and the strategic placement of the SC80 satellite. Forecasting of geoeffective space weather events is possible thanks to an accurate surveillance of the magnetic energy buildup in the Sun, an optical tracking through the interplanetary space, and in-situ measurements of the near-Earth environment.

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, Aug 1, 2018

We present compression and instrumented indentation experiments on high-purity Indium, at tempera... more We present compression and instrumented indentation experiments on high-purity Indium, at temperatures from 22 to-100°C. A strong indentation size effect is detected at all temperatures, corresponding to a large material length-scale. Therefore the large length-scale is not a consequence of creep mechanisms but an intrinsic property of the material.

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2013

This paper forms part of the 'Everplane' Group Design Project and aims to present... more This paper forms part of the 'Everplane' Group Design Project and aims to present the Vehicle Definition of an autonomous high-altitude long-endurance concept aircraft, designed for flying continuously over one month in an environmentally sustainable manner. The platform has the capability of acting as an aerosattelite, providing affordable internet to remote areas. Note that this report is part of a group of 20 approaching this design challenge from different perspectives. The focus points of this particular report are: initial and final aircraft configuration design; accurate mass and centre of gravity determination; computer-aided design for technical (CFD, FEA, Drawings) and media (rendering) purposes. The results, consistent with previous studies, indicate that an optimum configuration is a conventional one, featuring a high aspect ratio wing, a cruciform tail, 4 electric engines powered by H2 fuel cells, recharged by a large solar panel array. Furthermore, the total mass for the most recent aircraft iteration was determined as 539.65kg, within the flight allowance of 559kg. Finally, the concept was determined to be technically feasible from the perspective of all teams involved.

Materials Science and Engineering: A, 2017

Tension, compression, three-point bending and indentation experiments are conducted on high purit... more Tension, compression, three-point bending and indentation experiments are conducted on high purity Indium at room temperature and low strain rates. The material displays a ductile viscoplastic response, found to be size-independent in tension and compression. Simple analytical models are constructed to aid interpretation of the test results and detection of a size effect in bending and indentation, associated to a length-scale of order 50-100 µm.

Journal of Space Weather and Space Climate, 2015

An accurate forecast of flare and CME initiation requires precise measurements of the magnetic en... more An accurate forecast of flare and CME initiation requires precise measurements of the magnetic energy build up and release in the active regions of the solar atmosphere. We designed a new space weather mission that performs such measurements using new optical instruments based on the Hanle and Zeeman effects. The mission consists of two satellites, one orbiting the L1 Lagrangian point (Spacecraft Earth, SCE) and the second in heliocentric orbit at 1AU trailing the Earth by 80 • (Spacecraft 80, SC80). Optical instruments measure the vector magnetic field in multiple layers of the solar atmosphere. The location of the spacecrafts allow for a continuous imaging of nearly 73% of the total solar surface. In-situ plasma instruments placed in the SCE detect solar wind conditions in the near Earth environment. Earth directed CMEs can be tracked thanks to the stereoscopic view Jorge Amaya et al.: PAC2MAN: a new tool to understand and predict solar energetic events of the spacecrafts and the strategic placement of the SC80 satellite. Forecasting of geoeffective space weather events is possible thanks to an accurate surveillance of the magnetic energy build up in the Sun, an optical tracking through the interplanetary space, and in-situ measurements of the near-Earth environment.

Tapping no. Angle (°) Angle (rad) Manoneter reading (inch C 2 H 6 O) Manoneter reading (mm C2H6O)... more Tapping no. Angle (°) Angle (rad) Manoneter reading (inch C 2 H 6 O) Manoneter reading (mm C2H6O) Corection for 30° incline (mm C2H6O) P-P∞ (Pa) Cp Cd uncorected Trapezoidal integration Cl uncorected Trapezoidal integration Cp Corrected Cd Corrected Cl Corrected Cp Potential D'Alambert Flow no. Angle (°) Angle (rad) Manoneter reading (inch C 2 H 6 O) Manoneter reading (mm C2H6O) Corection for 40° incline (mm C2H6O) P-P∞ (Pa) Cp Cd uncorected Trapezoidal integration Cl uncorected Trapezoidal integration Cp Corrected Cd Corrected Cl Corrected Cp Potential D'Alamb ert Flow

The experiment was performed in the Donald Campbell Wind Tunnel Laboratory on the 26 th of Februa... more The experiment was performed in the Donald Campbell Wind Tunnel Laboratory on the 26 th of February, under the supervision of Mr Ben Clapperton with the objective of determining the lift and drag coefficients of a Cessna 172 airplane at various angles of attack (AOA) and two air speeds. After the analysis of data gathered from the test, the Reynolds numbers have been determined and various plots have been created to show the evolution of lift and drag with change of AOA. The effects of induced drag have been observed visually and found numerically, also the stall speed of the real plane has been estimated. Following a comparison with the actual value of 26m/s (Lab Handout, 2012) the impact of wind tunnel blockage effects could be observed.

The experiment was performed in the Strain Measurement laboratory on the 12th of November, under ... more The experiment was performed in the Strain Measurement laboratory on the 12th of November, under the supervision of Mr Yuefeng Cui with the objective of determining the Young modulus and Poisson Ration of a sample of steel material using resistance strain gauges at room temperature. After the analysis of raw data gathered from the test, the average values of the two parameters sought have been calculated. After subjecting them to a comparison with previous experimental determinations (Luecke, et al., 2006, pp. 46-47), (Toolbox, 2012) and (Toolbox, 2012) it is reasonable to state that the values obtained are feasible and a good approximation of the real material properties.

We have designed a concept airplane in order to analyze the feasibility of passenger flight can b... more We have designed a concept airplane in order to analyze the feasibility of passenger flight can be an ecological, no-emissions, means of travelling. Using relevant facts as well as combining conventional technology with well-researched concepts we hope to achieve realistic design, as far as our knowledge in high school can reach, that can be analyzed further by specialists. The project is based on our original idea and the information provided justifies our choices.

Following the wind tunnel testing of a swept uniformly tapered half wing with straight edges at a... more Following the wind tunnel testing of a swept uniformly tapered half wing with straight edges at an average Re number of 5E+05 and at 6 angles of attack (0, 4, 6, 9, 11, 15), pressure distribution data for three sections was obtained. This paper assesses the reliability of the inviscid computational ‘panel method’ and thin aerofoil theory in predicting wing performance, though comparison with experimental data. Both the validity of the data and its interpretation were confirmed, upon comparison with similar papers. Uncertainties were accounted for. Furthermore, the report presents the advantages, limitations and importance of inviscid methods in swept-back wing design and analyses the stalling behavior of the wing.

Our team has analyzed the possible purpose of our colony ship in the future, by thinking of plaus... more Our team has analyzed the possible purpose of our colony ship in the future, by thinking of plausible futuristic scenarios. We designed our project for a relevant and clear representation of the colony and the life an inhabitant would have aboard it. By combining 3D graphics with scientific concepts we hoped to create a clear depiction of all issues that make up the station, from its creation to the social structure and they way it is sustained by life support systems. At the end of each chapter we imagined scenario in a short narration to illustrate how the proposed design affects inhabitants.

Matlab Implementation of the following: Finite Order Approximation Heat equation solution Integra... more Matlab Implementation of the following: Finite Order Approximation Heat equation solution Integration Method Mid-Point Rule vs. Gauss-Legendre Rule Trapezium Rule vs. Gauss-Legendre Rule Number Storage Bisection Method Newton-Raphson Method Secant Method

Materials Science and Engineering: A

We present compression and instrumented indentation experiments on high-purity Indium, at tempera... more We present compression and instrumented indentation experiments on high-purity Indium, at temperatures from 22 to-100°C. A strong indentation size effect is detected at all temperatures, corresponding to a large material length-scale. Therefore the large length-scale is not a consequence of creep mechanisms but an intrinsic property of the material.

Journal of Space Weather and Space Climate, 2015

An accurate forecast of flare and coronal mass ejection (CME) initiation requires precise measure... more An accurate forecast of flare and coronal mass ejection (CME) initiation requires precise measurements of the magnetic energy buildup and release in the active regions of the solar atmosphere. We designed a new space weather mission that performs such measurements using new optical instruments based on the Hanle and Zeeman effects. The mission consists of two satellites, one orbiting the L1 Lagrangian point (Spacecraft Earth, SCE) and the second in heliocentric orbit at 1AU trailing the Earth by 80°(Spacecraft 80, SC80). Optical instruments measure the vector magnetic field in multiple layers of the solar atmosphere. The orbits of the spacecraft allow for a continuous imaging of nearly 73% of the total solar surface. In-situ plasma instruments detect solar wind conditions at 1AU and ahead of our planet. Earth-directed CMEs can be tracked using the stereoscopic view of the spacecraft and the strategic placement of the SC80 satellite. Forecasting of geoeffective space weather events is possible thanks to an accurate surveillance of the magnetic energy buildup in the Sun, an optical tracking through the interplanetary space, and in-situ measurements of the near-Earth environment.

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, Aug 1, 2018

We present compression and instrumented indentation experiments on high-purity Indium, at tempera... more We present compression and instrumented indentation experiments on high-purity Indium, at temperatures from 22 to-100°C. A strong indentation size effect is detected at all temperatures, corresponding to a large material length-scale. Therefore the large length-scale is not a consequence of creep mechanisms but an intrinsic property of the material.

HAL (Le Centre pour la Communication Scientifique Directe), Nov 1, 2013

This paper forms part of the 'Everplane' Group Design Project and aims to present... more This paper forms part of the 'Everplane' Group Design Project and aims to present the Vehicle Definition of an autonomous high-altitude long-endurance concept aircraft, designed for flying continuously over one month in an environmentally sustainable manner. The platform has the capability of acting as an aerosattelite, providing affordable internet to remote areas. Note that this report is part of a group of 20 approaching this design challenge from different perspectives. The focus points of this particular report are: initial and final aircraft configuration design; accurate mass and centre of gravity determination; computer-aided design for technical (CFD, FEA, Drawings) and media (rendering) purposes. The results, consistent with previous studies, indicate that an optimum configuration is a conventional one, featuring a high aspect ratio wing, a cruciform tail, 4 electric engines powered by H2 fuel cells, recharged by a large solar panel array. Furthermore, the total mass for the most recent aircraft iteration was determined as 539.65kg, within the flight allowance of 559kg. Finally, the concept was determined to be technically feasible from the perspective of all teams involved.

Materials Science and Engineering: A, 2017

Tension, compression, three-point bending and indentation experiments are conducted on high purit... more Tension, compression, three-point bending and indentation experiments are conducted on high purity Indium at room temperature and low strain rates. The material displays a ductile viscoplastic response, found to be size-independent in tension and compression. Simple analytical models are constructed to aid interpretation of the test results and detection of a size effect in bending and indentation, associated to a length-scale of order 50-100 µm.

Journal of Space Weather and Space Climate, 2015

An accurate forecast of flare and CME initiation requires precise measurements of the magnetic en... more An accurate forecast of flare and CME initiation requires precise measurements of the magnetic energy build up and release in the active regions of the solar atmosphere. We designed a new space weather mission that performs such measurements using new optical instruments based on the Hanle and Zeeman effects. The mission consists of two satellites, one orbiting the L1 Lagrangian point (Spacecraft Earth, SCE) and the second in heliocentric orbit at 1AU trailing the Earth by 80 • (Spacecraft 80, SC80). Optical instruments measure the vector magnetic field in multiple layers of the solar atmosphere. The location of the spacecrafts allow for a continuous imaging of nearly 73% of the total solar surface. In-situ plasma instruments placed in the SCE detect solar wind conditions in the near Earth environment. Earth directed CMEs can be tracked thanks to the stereoscopic view Jorge Amaya et al.: PAC2MAN: a new tool to understand and predict solar energetic events of the spacecrafts and the strategic placement of the SC80 satellite. Forecasting of geoeffective space weather events is possible thanks to an accurate surveillance of the magnetic energy build up in the Sun, an optical tracking through the interplanetary space, and in-situ measurements of the near-Earth environment.

Tapping no. Angle (°) Angle (rad) Manoneter reading (inch C 2 H 6 O) Manoneter reading (mm C2H6O)... more Tapping no. Angle (°) Angle (rad) Manoneter reading (inch C 2 H 6 O) Manoneter reading (mm C2H6O) Corection for 30° incline (mm C2H6O) P-P∞ (Pa) Cp Cd uncorected Trapezoidal integration Cl uncorected Trapezoidal integration Cp Corrected Cd Corrected Cl Corrected Cp Potential D'Alambert Flow no. Angle (°) Angle (rad) Manoneter reading (inch C 2 H 6 O) Manoneter reading (mm C2H6O) Corection for 40° incline (mm C2H6O) P-P∞ (Pa) Cp Cd uncorected Trapezoidal integration Cl uncorected Trapezoidal integration Cp Corrected Cd Corrected Cl Corrected Cp Potential D'Alamb ert Flow

The experiment was performed in the Donald Campbell Wind Tunnel Laboratory on the 26 th of Februa... more The experiment was performed in the Donald Campbell Wind Tunnel Laboratory on the 26 th of February, under the supervision of Mr Ben Clapperton with the objective of determining the lift and drag coefficients of a Cessna 172 airplane at various angles of attack (AOA) and two air speeds. After the analysis of data gathered from the test, the Reynolds numbers have been determined and various plots have been created to show the evolution of lift and drag with change of AOA. The effects of induced drag have been observed visually and found numerically, also the stall speed of the real plane has been estimated. Following a comparison with the actual value of 26m/s (Lab Handout, 2012) the impact of wind tunnel blockage effects could be observed.

The experiment was performed in the Strain Measurement laboratory on the 12th of November, under ... more The experiment was performed in the Strain Measurement laboratory on the 12th of November, under the supervision of Mr Yuefeng Cui with the objective of determining the Young modulus and Poisson Ration of a sample of steel material using resistance strain gauges at room temperature. After the analysis of raw data gathered from the test, the average values of the two parameters sought have been calculated. After subjecting them to a comparison with previous experimental determinations (Luecke, et al., 2006, pp. 46-47), (Toolbox, 2012) and (Toolbox, 2012) it is reasonable to state that the values obtained are feasible and a good approximation of the real material properties.

We have designed a concept airplane in order to analyze the feasibility of passenger flight can b... more We have designed a concept airplane in order to analyze the feasibility of passenger flight can be an ecological, no-emissions, means of travelling. Using relevant facts as well as combining conventional technology with well-researched concepts we hope to achieve realistic design, as far as our knowledge in high school can reach, that can be analyzed further by specialists. The project is based on our original idea and the information provided justifies our choices.

Following the wind tunnel testing of a swept uniformly tapered half wing with straight edges at a... more Following the wind tunnel testing of a swept uniformly tapered half wing with straight edges at an average Re number of 5E+05 and at 6 angles of attack (0, 4, 6, 9, 11, 15), pressure distribution data for three sections was obtained. This paper assesses the reliability of the inviscid computational ‘panel method’ and thin aerofoil theory in predicting wing performance, though comparison with experimental data. Both the validity of the data and its interpretation were confirmed, upon comparison with similar papers. Uncertainties were accounted for. Furthermore, the report presents the advantages, limitations and importance of inviscid methods in swept-back wing design and analyses the stalling behavior of the wing.

Our team has analyzed the possible purpose of our colony ship in the future, by thinking of plaus... more Our team has analyzed the possible purpose of our colony ship in the future, by thinking of plausible futuristic scenarios. We designed our project for a relevant and clear representation of the colony and the life an inhabitant would have aboard it. By combining 3D graphics with scientific concepts we hoped to create a clear depiction of all issues that make up the station, from its creation to the social structure and they way it is sustained by life support systems. At the end of each chapter we imagined scenario in a short narration to illustrate how the proposed design affects inhabitants.

Matlab Implementation of the following: Finite Order Approximation Heat equation solution Integra... more Matlab Implementation of the following: Finite Order Approximation Heat equation solution Integration Method Mid-Point Rule vs. Gauss-Legendre Rule Trapezium Rule vs. Gauss-Legendre Rule Number Storage Bisection Method Newton-Raphson Method Secant Method

Materials Science and Engineering: A

We present compression and instrumented indentation experiments on high-purity Indium, at tempera... more We present compression and instrumented indentation experiments on high-purity Indium, at temperatures from 22 to-100°C. A strong indentation size effect is detected at all temperatures, corresponding to a large material length-scale. Therefore the large length-scale is not a consequence of creep mechanisms but an intrinsic property of the material.