The Experts below are selected from a list of 1512 Experts worldwide ranked by ideXlab platform
Masoud Farzaneh - One of the best experts on this subject based on the ideXlab platform.
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ice repellency behaviour of superhydrophobic surfaces effects of atmospheric Icing Conditions and surface roughness
Applied Surface Science, 2015Co-Authors: Gelareh Momen, Reza Jafari, Masoud FarzanehAbstract:This paper presents a novel view on ice repellency of superhydrophobic surfaces in terms of contact angle hysteresis, surface roughness and Icing Condition. Ice repellency performance of two superhydrophobic silicone rubber nanocomposite surfaces prepared via spin coating and spray coating methods were investigated. High contact angle (>150°), low contact angle hysteresis (<6°) and roll-off property were found for both spin and spray coated samples. The results showed a significant reduction of ice adhesion strength on the spin-coated sample while ice adhesion strength on the spray-coated sample was found to be unexpectedly similar to that of the uncoated sample. Indeed, this research study showed that the icephobic properties of a surface are not directly correlated to its superhydrphobicity and that further investigations, like taking Icing Condition effect into account, are required. It was found that icephobic behaviour of the spray coated sample improved at lower levels of liquid water content (LWC) and under Icing Conditions characterized by smaller water droplet size.
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Ice repellency behaviour of superhydrophobic surfaces: Effects of atmospheric Icing Conditions and surface roughness
Applied Surface Science, 2015Co-Authors: Gelareh Momen, Reza Jafari, Masoud FarzanehAbstract:This paper presents a novel view on ice repellency of superhydrophobic surfaces in terms of contact angle hysteresis, surface roughness and Icing Condition. Ice repellency performance of two superhydrophobic silicone rubber nanocomposite surfaces prepared via spin coating and spray coating methods were investigated. High contact angle (>150°), low contact angle hysteresis (
Gelareh Momen - One of the best experts on this subject based on the ideXlab platform.
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ice repellency behaviour of superhydrophobic surfaces effects of atmospheric Icing Conditions and surface roughness
Applied Surface Science, 2015Co-Authors: Gelareh Momen, Reza Jafari, Masoud FarzanehAbstract:This paper presents a novel view on ice repellency of superhydrophobic surfaces in terms of contact angle hysteresis, surface roughness and Icing Condition. Ice repellency performance of two superhydrophobic silicone rubber nanocomposite surfaces prepared via spin coating and spray coating methods were investigated. High contact angle (>150°), low contact angle hysteresis (<6°) and roll-off property were found for both spin and spray coated samples. The results showed a significant reduction of ice adhesion strength on the spin-coated sample while ice adhesion strength on the spray-coated sample was found to be unexpectedly similar to that of the uncoated sample. Indeed, this research study showed that the icephobic properties of a surface are not directly correlated to its superhydrphobicity and that further investigations, like taking Icing Condition effect into account, are required. It was found that icephobic behaviour of the spray coated sample improved at lower levels of liquid water content (LWC) and under Icing Conditions characterized by smaller water droplet size.
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Ice repellency behaviour of superhydrophobic surfaces: Effects of atmospheric Icing Conditions and surface roughness
Applied Surface Science, 2015Co-Authors: Gelareh Momen, Reza Jafari, Masoud FarzanehAbstract:This paper presents a novel view on ice repellency of superhydrophobic surfaces in terms of contact angle hysteresis, surface roughness and Icing Condition. Ice repellency performance of two superhydrophobic silicone rubber nanocomposite surfaces prepared via spin coating and spray coating methods were investigated. High contact angle (>150°), low contact angle hysteresis (
Reza Jafari - One of the best experts on this subject based on the ideXlab platform.
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ice repellency behaviour of superhydrophobic surfaces effects of atmospheric Icing Conditions and surface roughness
Applied Surface Science, 2015Co-Authors: Gelareh Momen, Reza Jafari, Masoud FarzanehAbstract:This paper presents a novel view on ice repellency of superhydrophobic surfaces in terms of contact angle hysteresis, surface roughness and Icing Condition. Ice repellency performance of two superhydrophobic silicone rubber nanocomposite surfaces prepared via spin coating and spray coating methods were investigated. High contact angle (>150°), low contact angle hysteresis (<6°) and roll-off property were found for both spin and spray coated samples. The results showed a significant reduction of ice adhesion strength on the spin-coated sample while ice adhesion strength on the spray-coated sample was found to be unexpectedly similar to that of the uncoated sample. Indeed, this research study showed that the icephobic properties of a surface are not directly correlated to its superhydrphobicity and that further investigations, like taking Icing Condition effect into account, are required. It was found that icephobic behaviour of the spray coated sample improved at lower levels of liquid water content (LWC) and under Icing Conditions characterized by smaller water droplet size.
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Ice repellency behaviour of superhydrophobic surfaces: Effects of atmospheric Icing Conditions and surface roughness
Applied Surface Science, 2015Co-Authors: Gelareh Momen, Reza Jafari, Masoud FarzanehAbstract:This paper presents a novel view on ice repellency of superhydrophobic surfaces in terms of contact angle hysteresis, surface roughness and Icing Condition. Ice repellency performance of two superhydrophobic silicone rubber nanocomposite surfaces prepared via spin coating and spray coating methods were investigated. High contact angle (>150°), low contact angle hysteresis (
Yang Liu - One of the best experts on this subject based on the ideXlab platform.
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an experimental study on dynamic ice accretion process over the surfaces of rotating aero engine spinners
Experimental Thermal and Fluid Science, 2019Co-Authors: Yang LiuAbstract:Abstract An experimental study was conducted to investigate the dynamic ice accretion process over the surfaces of rotating aero-engine spinners and to examine the detriment effects of the ice accretion on the airflow to be inhaled by aero-engines. Three scaled spinner-fan models with different spinner shapes (i.e., conical-shaped, coniptical-shaped, and elliptical-shaped spinners) were manufactured and exposed under typical rime and glaze Icing Conditions for a comparative study. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion process over the rotating spinner models, a high-resolution particle image velocimetry (PIV) system was utilized to examine the trajectories of super-cooled water droplets as they approach to the surfaces of the spinner models. It was found that, under typical rime Conditions, while accreted ice layers were found to conform well with the original shapes of the spinner models in general, the total amount of the ice mass accreted over the spinner surfaces were found to be a strong dependent on the spinner shapes. While the conical-shaped spinner was found to have the largest amount of ice accretion (i.e., 60–80% more than those over the other two spinner models) over almost entire spinner surface, ice accretion was found to take place mainly in the front portion of the coniptical-shaped and elliptical-shaped spinners. Under the glaze Icing Condition, in addition to forming ice layers over the spinner surfaces, very complicated, needle-shaped icicles were also found to grow rapidly out from the spinner surfaces and extrude into the incoming airflow, due to the effects of the centrifugal forces associated with the rotation motion. The complex glaze ice structures accreted over the spinner surface were found to induce significant disturbances/distortions and even cause large-scale flow separations for the airflow near the iced spinner surfaces, which would significantly degrade the quality of the inlet airflow to be inhaled by aero-engines, thereby, adversely affecting the performance of aero-engines.
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an experimental investigation of dynamic ice accretion process on a wind turbine airfoil model considering various Icing Conditions
International Journal of Heat and Mass Transfer, 2019Co-Authors: Linyue Gao, Yang LiuAbstract:Abstract In the present study, the dynamic ice accretion process over a typical wind turbine airfoil model (i.e., DU96-W-180 airfoil) was experimentally investigated under various Icing Conditions. The experimental study was conducted in the Icing Research Tunnel of Iowa State University (i.e., ISU-IRT). Different Icing Conditions (i.e., rime, mixed and glaze) that wind turbine may experience in winter were reproduced by manipulating the airflow temperature, velocity, and liquid water content (LWC) in ISU-IRT. While a high-speed imaging system was used to reveal the dynamic ice accretion process over the surface of the test model, an infrared (IR) thermal imaging system was used to map the corresponding temperature distributions over the ice accreting airfoil surface. Time variations of the ice thickness accreted along the leading edge (LE) of the test model were extracted based on the acquired high-resolution images of the ice accretion process under different test Conditions. It was found that, due to the obvious runback of the impacted water (i.e., formation of water film and rivulets) over the airfoil surface, the growth rate of the ice layer accreted along the airfoil leading edge was much slower under the glaze Icing Condition, in comparison with those under the rime and mixed Icing Conditions. Such surface water transport behavior was also found to expand the ice influencing region. From the temperature evolutions during the dynamic Icing processes, the transient processes of droplet impingement, water film/rivulets formation, and ice roughness growth were temporally resolved, providing comprehensive details of the unsteady heat transfer during the dynamic Icing process. While the surface temperature increment due to the direct droplet impingement was found to decrease monotonously along the chord in rime case, a stream-wise ‘plateau’ region was observed in the glaze and mixed Icing cases due to the complex multiphase mass/heat transfer associated with the surface water transport behaviors.
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effects of thermal conductivity of airframe substrate on the dynamic ice accretion process pertinent to uas inflight Icing phenomena
International Journal of Heat and Mass Transfer, 2019Co-Authors: Yang Liu, Zichen ZhangAbstract:Abstract An experimental investigation was conducted to quantify the dynamic ice accretion and the unsteady heat transfer process over the ice accreting surfaces of composite-based airframes widely used for light-weight, Unmanned-Aerial-Systems (UAS), in comparison to those over the surfaces of metal-based airframes used by conventional manned aircraft, in order to elucidate the underlying Icing physics specifically pertinent to UAS inflight Icing phenomena. Two airfoil/wing models with the same airfoil shape, but made of different materials (i.e., thermoplastic material with the thermal conductivity being only ∼0.2 W/m⋅K to represent typical UAS airframe substrates vs. Aluminum with the thermal conductivity being ∼200 W/m⋅K widely used for conventional manned aircraft). The two test models were mounted side-by-side inside an Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT) under the same wet glaze or dry rime Icing Condition. During the Icing experiment, while a high-speed imaging system was used to record the dynamic ice accretion process over the surfaces of the test models, an infrared thermal imaging system was also used to map the corresponding surface temperature distributions over the ice accreting airfoil surfaces. It was found that, upon the impacting of the airborne, super-cooled water droplets in ISU-IRT, ice would start to accrete rapidly on the surfaces of the test models with a significant amount of the latent heat of fusion being released associated with the phase changing of the impacted super-cooled water mass over the airfoil surfaces. The thermal conductivity of the airframe substrate was found to affect the dynamic ice accretion and unsteady heat transfer processes over the ice accreting surfaces significantly. With the two test models being exposed under the same Icing Conditions, the released latent heat of fusion was found to be dissipated much slower over the surface of the thermoplastic model, due to the much lower thermal conductivity of the thermoplastic substrate. In comparison with those on the surface of the Aluminum model, the slower dissipation of the released latent heat of fusion on the surface of the thermoplastic model was found to cause higher surface temperatures and greater “heated” regions near the airfoil leading edge, more obvious surface water runback over the airfoil surface, and formation of more complex rivulet-shaped ice structures at further downstream locations beyond the direct impinging zone of the super-cooled water droplets.
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A comparison study on the thermal effects in DBD plasma actuation and electrical heating for aircraft Icing mitigation
International Journal of Heat and Mass Transfer, 2018Co-Authors: Yang Liu, Cem KolbakirAbstract:Abstract A comparison study of a novel method of utilizing thermal effects induced by Dielectric-Barrier-Discharge (DBD) plasma actuation (i.e., DBD plasma-based method) and a conventional electrical heating method for aircraft Icing mitigation was performed in an Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT). A NACA0012 airfoil/wing model embedded with an AC-DBD plasma actuator and a conventional electrical film heater over the airfoil surface was tested under a typical aircraft Icing Condition. While a high-speed imaging system was used to record the dynamic ice accretion and transient surface water transport processes over the airfoil surface, an infrared (IR) thermal imaging system was also utilized to map the corresponding surface temperature distributions over the airfoil surface simultaneously to quantify the unsteady heat transfer and phase changing process over the ice accreting airfoil surface. It was found that, with the same power input, the DBD plasma-based method showed at least equivalent effectiveness, if not better, in preventing ice accretion over the airfoil surface, in comparison to the conventional electrical heating method. Further optimization of the DBD plasma-based method with a duty-cycle modulation was found to have a much better anti-/de-Icing performance, in comparison to the conventional electrical heating method. The findings derived from the present study demonstrated the potential of a new class of anti-/de-Icing strategy by leveraging the thermal effects induced by DBD plasma actuation for aircraft in-flight Icing mitigation.
Wenwu Zhou - One of the best experts on this subject based on the ideXlab platform.
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an experimental study on the aerodynamic performance degradation of a wind turbine blade model induced by ice accretion process
Renewable Energy, 2019Co-Authors: Wenwu Zhou, Hui HuAbstract:Abstract An experimental study was conducted to characterize aerodynamic performance degradation of wind turbine blades induced by dynamic ice accretion process. The experimental study was performed in an Icing Research Tunnel with a turbine blade model under a typical glaze Icing Condition. Ice structures were found to accrete rapidly over both the upper and lower surfaces of the blade model after starting the ice accretion experiment. Irregular-shaped ice structures were found to disturb the airflow around the blade model greatly, resulting in large-scale flow separations and shedding of unsteady vortex structures from the ice accreting surface. The aerodynamic performance of the blade model was found to degrade significantly. The performance degradation induced by the ice accretion was found to be a strong function of the angle of attack of the blade model with more significant degradations at lower angles of attack. For the test case at the angle of attack of 5.0°, while the lift decreases to only ∼12% of its original value after 600 s of the ice accretion experiment, the drag was found to increase 4.5 times correspondingly. The detailed flow field measurements were correlated with the aerodynamic force data to elucidate the underlying physics.
