The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
J. K. Prasad - One of the best experts on this subject based on the ideXlab platform.
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effect of multiple rings on side force over an ogive cylinder body at Subsonic Speed
Chinese Journal of Aeronautics, 2018Co-Authors: P. Kumar, J. K. PrasadAbstract:Abstract Experiments and computations were performed over an ogive-cylinder body having an lift-to-drag ratio of 16 at a diameter Reynolds number of 29000. The side force on the slender body augments with increasing angles of attack for the case without a ring. This increase was mainly due to the increase in the asymmetry of the existing vortex pair in the wake of the body. Attempts were made to completely reduce the existing side force at the angle of attack ranging from 35° to 45°. Three rectangular cross-sectioned circumferential rings having a height of 3% of the local diameter were placed at axial distances of 2.5, 3.5 and 4.5 times the base diameter from the tip of the body so as to reduce the side force. The results obtained indicate that inclusion of three rings completely alleviated the side force on the slender body at the angle of attack ranging from 0° to 45°. The presence of rings was found to alter the growth of the vortices that helped in the reduction of the side force. Computations performed were in reasonable agreement with the experiments.
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Effect of multiple rings on side force over an ogive-cylinder body at Subsonic Speed
Elsevier, 2018Co-Authors: Priyank Kumar, J. K. PrasadAbstract:Experiments and computations were performed over an ogive-cylinder body having an lift-to-drag ratio of 16 at a diameter Reynolds number of 29000. The side force on the slender body augments with increasing angles of attack for the case without a ring. This increase was mainly due to the increase in the asymmetry of the existing vortex pair in the wake of the body. Attempts were made to completely reduce the existing side force at the angle of attack ranging from 35° to 45°. Three rectangular cross-sectioned circumferential rings having a height of 3% of the local diameter were placed at axial distances of 2.5, 3.5 and 4.5 times the base diameter from the tip of the body so as to reduce the side force. The results obtained indicate that inclusion of three rings completely alleviated the side force on the slender body at the angle of attack ranging from 0° to 45°. The presence of rings was found to alter the growth of the vortices that helped in the reduction of the side force. Computations performed were in reasonable agreement with the experiments. Keywords: Asymmetric vortex, High angle of attack, Ogive, Side force, Slender body, Vortex lif
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side force over slender body with rings at different location at Subsonic Speed
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering, 2017Co-Authors: P. Kumar, J. K. PrasadAbstract:Investigations have been made adopting experiments and computations on an ogive-nosed slender body at different angles of attack and Reynolds number of 29,000 based on the model base diameter diameter. The results indicated an increase in the side force at large angles of attack, which is mainly due to the presence of asymmetric vortices in the leeward of the body. The inclusion of a rectangular cross-sectioned ring in the initial portion of the body reduced the side force at higher angles of attack. However, significant side force was experienced at lower angles of attack (30° < α < 40°). Use of a ring of 3% height was found to be suitable for reducing the side force at a higher angle of attack. From the results obtained it was observed that a ring if placed at a different axial location alters the flow field and changes the side force at higher angles of attack. Further studies indicated that placing of rings pair at an axial location of 3.5 and 4.5 times the base diameter reduced the side force to a ve...
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effect of ring size on the side force over ogive cylinder body at Subsonic Speed
Aeronautical Journal, 2016Co-Authors: P. Kumar, J. K. PrasadAbstract:Experiments and computations have been made to obtain the details of the flow field over a slender body at high angles of attack at a freestream velocity of 17 m/s corresponding to a Reynolds number of 2.9×10 4 based on the base diameter. Experiments indicated that the existence of side force at higher angles of attack is mainly due to the presence of asymmetric vortices in the leeward side. A rectangular cross-section circular ring placed at an axial distance of 3.5 times the base diameter reduced the side force at all the angles of attack. Investigations were made to obtain the effect of the height of the ring at an angle-of-attack of 50° where the side force experienced is relatively large. A ring placed at a distance of 3.5 times the base diameter alters the initial vortices and hence helps in substantial reduction of the side force. Studies with rings of different heights indicate that a ring having a height of 3% of the local diameter reduced the side force at almost all the angles of attack for the present flow conditions and provided the least disturbance to the lift and drag of the body.
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Side force over slender body with rings at different location at Subsonic Speed
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering, 2016Co-Authors: P. Kumar, J. K. PrasadAbstract:Investigations have been made adopting experiments and computations on an ogive-nosed slender body at different angles of attack and Reynolds number of 29,000 based on the model base diameter diameter. The results indicated an increase in the side force at large angles of attack, which is mainly due to the presence of asymmetric vortices in the leeward of the body. The inclusion of a rectangular cross-sectioned ring in the initial portion of the body reduced the side force at higher angles of attack. However, significant side force was experienced at lower angles of attack (30°
C Breitsamter - One of the best experts on this subject based on the ideXlab platform.
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leading edge vortex interactions at a generic multiple swept wing aircraft configuration
Journal of Aircraft, 2019Co-Authors: S Pfnur, C BreitsamterAbstract:Experimental investigations on a generic low-aspect-ratio aircraft configuration with triple and double delta wing planforms were performed at Subsonic Speed. Flowfield measurements by means of ste...
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analysis of vortex flow phenomena on generic delta wing planforms at Subsonic Speeds
Symposium der Deutsche Gesellschaft für Luft- und Raumfahrt, 2018Co-Authors: S Pfnur, Jonathan Pfluger, C BreitsamterAbstract:Experimental and numerical investigations on the vortex dominated flow at a double and triple delta wing configuration at low Subsonic Speed are presented. Forces and moments obtained from wind tunnel tests and numerical simulations, as well as flow-field data obtained by stereo particle image velocimetry are discussed. The flow field is dominated by two interacting leading-edge vortices. The interaction of the vortices very much depends on the relative sweep of the leading-edges and ranges from independent movement via merging to a complex breakdown pattern of the vortex system. The loss of the strong interaction leads to a pitch up tendency and roll reversal. For the double delta wing, this happens at higher angles of attack and more abrupt, and therefore results in a sudden instability. The numerical results show a satisfying agreement with the wind tunnel data, but need further evaluation to clarify the usability for a more detailed analysis of the flow field.
Nor F. Reduan - One of the best experts on this subject based on the ideXlab platform.
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Wind Tunnel experiments of UiTM's blended wing body (BWB) Baseline-II unmanned aerial vehicle (UAV) at low Subsonic Speed
CSSR 2010 - 2010 International Conference on Science and Social Research, 2010Co-Authors: Firdaus Mohamad, Zurriati Mohd. Ali, Rizal Effendy M Nasir, Wahyu Kuntjoro Wirachman Wisnoe, Wahyu Kuntjoro, Nor F. ReduanAbstract:An experimental investigation is conducted to obtain aerodynamic characteristics and performance of a blended wing- body aircraft (BWB) under study by UiTM. The BWB design for unmanned aerial vehicle (UAV) known as “Baseline-II” is actually a completely-revised, redesigned version of “Baseline-I” BWB. The Baseline-II features have introduced a canard, a simpler planform, and slimmer body compared to its predecessor while maintaining wingspan. All tests are carried out in UiTM Low Speed Wind Tunnel using 1/6 scaled model of BWB at around 0.1 Mach number. The lift coefficient (CL), the drag coefficient (CD), the pitching moment coefficient (CM), and the Lift-to-Drag (L/D) ratio curves are then plotted at various angles of attack, including CL versus CD polar to show the performance of the BWB. The results obtained will show the aerodynamic
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Static stability of Baseline-II blended wing- body aircraft at low Subsonic Speed: Investigation via computational fluid dynamics simulation
2010 International Conference on Science and Social Research (CSSR 2010), 2010Co-Authors: Rizal Effendy Mohd Nasir, Wahyu Kuntjoro Wirachman Wisnoe, Nor F. Reduan, Wahyu Kuntjoro, Firdaus Mohamad, Zurriati Mohd Ali, Ramzyzan RamlyAbstract:A study of the effect of canard to Baseline-II blended wing-body aircraft is presented here with emphasis on investigating contributions of canard's various setting angle to aerodynamic parameters and longitudinal static stability. A computational fluid dynamic (CFD) simulation has been conducted at low Subsonic Speed to collect aerodynamic data and found that its aerodynamic trend is similar to many BWB aircraft and consistent to previous studies conducted in UiTM. Canard setting angle affects the value of lift-at-zero incidence of a BWB aircraft, although fairly small for current canard size that it is not adequate to produce positive pitching moment-at-zero lift. Baseline-II is partially, statically stable in longitudinal motion because of negative moment change w.r.t. lift change but it has equilibrium incidence angle that only produces negative lift. Larger canard and/or modification to Baseline-II wing-body are needed to overcome this flaw. The location of new reference point provides ‘comfortable’ static margin. Data and mathematical characteristic obtained from BL-IIA SP CFD simulation is comparable to those from wind tunnel experiment and both show satisfactory-to-good correlation to theoretical calculations.
P. Kumar - One of the best experts on this subject based on the ideXlab platform.
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effect of multiple rings on side force over an ogive cylinder body at Subsonic Speed
Chinese Journal of Aeronautics, 2018Co-Authors: P. Kumar, J. K. PrasadAbstract:Abstract Experiments and computations were performed over an ogive-cylinder body having an lift-to-drag ratio of 16 at a diameter Reynolds number of 29000. The side force on the slender body augments with increasing angles of attack for the case without a ring. This increase was mainly due to the increase in the asymmetry of the existing vortex pair in the wake of the body. Attempts were made to completely reduce the existing side force at the angle of attack ranging from 35° to 45°. Three rectangular cross-sectioned circumferential rings having a height of 3% of the local diameter were placed at axial distances of 2.5, 3.5 and 4.5 times the base diameter from the tip of the body so as to reduce the side force. The results obtained indicate that inclusion of three rings completely alleviated the side force on the slender body at the angle of attack ranging from 0° to 45°. The presence of rings was found to alter the growth of the vortices that helped in the reduction of the side force. Computations performed were in reasonable agreement with the experiments.
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side force over slender body with rings at different location at Subsonic Speed
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering, 2017Co-Authors: P. Kumar, J. K. PrasadAbstract:Investigations have been made adopting experiments and computations on an ogive-nosed slender body at different angles of attack and Reynolds number of 29,000 based on the model base diameter diameter. The results indicated an increase in the side force at large angles of attack, which is mainly due to the presence of asymmetric vortices in the leeward of the body. The inclusion of a rectangular cross-sectioned ring in the initial portion of the body reduced the side force at higher angles of attack. However, significant side force was experienced at lower angles of attack (30° < α < 40°). Use of a ring of 3% height was found to be suitable for reducing the side force at a higher angle of attack. From the results obtained it was observed that a ring if placed at a different axial location alters the flow field and changes the side force at higher angles of attack. Further studies indicated that placing of rings pair at an axial location of 3.5 and 4.5 times the base diameter reduced the side force to a ve...
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effect of ring size on the side force over ogive cylinder body at Subsonic Speed
Aeronautical Journal, 2016Co-Authors: P. Kumar, J. K. PrasadAbstract:Experiments and computations have been made to obtain the details of the flow field over a slender body at high angles of attack at a freestream velocity of 17 m/s corresponding to a Reynolds number of 2.9×10 4 based on the base diameter. Experiments indicated that the existence of side force at higher angles of attack is mainly due to the presence of asymmetric vortices in the leeward side. A rectangular cross-section circular ring placed at an axial distance of 3.5 times the base diameter reduced the side force at all the angles of attack. Investigations were made to obtain the effect of the height of the ring at an angle-of-attack of 50° where the side force experienced is relatively large. A ring placed at a distance of 3.5 times the base diameter alters the initial vortices and hence helps in substantial reduction of the side force. Studies with rings of different heights indicate that a ring having a height of 3% of the local diameter reduced the side force at almost all the angles of attack for the present flow conditions and provided the least disturbance to the lift and drag of the body.
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Side force over slender body with rings at different location at Subsonic Speed
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering, 2016Co-Authors: P. Kumar, J. K. PrasadAbstract:Investigations have been made adopting experiments and computations on an ogive-nosed slender body at different angles of attack and Reynolds number of 29,000 based on the model base diameter diameter. The results indicated an increase in the side force at large angles of attack, which is mainly due to the presence of asymmetric vortices in the leeward of the body. The inclusion of a rectangular cross-sectioned ring in the initial portion of the body reduced the side force at higher angles of attack. However, significant side force was experienced at lower angles of attack (30°
Li Jianguo - One of the best experts on this subject based on the ideXlab platform.
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Comparison Between Wear Resistance of Subsonic Speed Flame Spraying Coating and Plasma Spraying Coating
Hot Working Technology, 2008Co-Authors: Li JianguoAbstract:The Fe-WC metal ceramics coatings were prepared by Subsonic Speed flame spraying and plasma spraying and the wear resistance of the two kinds of coatings was studied.The results indicate that the attrition value of plasma spraying coating is more stable than that of Subsonic Speed flame spraying coating during the experiment process,the wear resistance of plasma spraying coating is much better than that of Subsonic Speed flame spraying coating.
