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Romero Pérez María - One of the best experts on this subject based on the ideXlab platform.
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Sobre la mitigación de la separación de la corriente en perfiles aerodinámicos a bajo número de Reynolds
2020Co-Authors: Romero Pérez MaríaAbstract:[ES] El estudio de la aerodinámica a bajo número de Reynolds resulta fundamental debido al auge de las pequeñas aeronaves no tripuladas que vuelan a dicho régimen, cada vez más empleadas por las ventajas que suponen. El principal fenómeno que se estudiará consiste en la aparición de burbujas de separación laminar, producidas cuando el flujo se desprende de la superficie del perfil para después volver a adherirse, modificando así su actuación aerodinámica. Con tal de evitar la aparición de esta burbuja, se fija como objetivo mitigar la separación de la corriente a través de la incorporación de succión y eyección en el perfil estudiado. De este modo y abarcando cuatro números de Reynolds distintos, se tratará de aumentar la eficiencia aerodinámica durante el vuelo de crucero a partir de un estudio paramétrico que permita encontrar el diseño óptimo. Por otro lado, se buscará incrementar el coeficiente de sustentación máximo con tal de poder dotar al vehículo de una mayor masa de despegue para cierta velocidad o, por el contrario, reducir la velocidad de entrada en pérdida para una masa concreta. Con estos objetivos en mente, se empleará el programa XFLR5 y la dinámica de fluidos computacional para el correspondiente desarrollo del trabajo.[EN] The study of low Reynolds number aerodynamics is essencial due to the rise of small unmanned aerial vehicles flying under this regime, increasingly used for the advantages they represent. The main phenomenon that is studied in this paper is the appearance of laminar separation bubbles (LSB), where the flow detaches from the profile surface and then it adheres again, causing the modification of its aerodynamic performance. In order to avoid the appearance of this bubble, the objective is to mitigate the separation of the stream with the incorporation of suction and ejection in the studied profile. Using four different Reynolds numbers, an attempt will be made to increase aerodynamic efficiency during cruise from a parametric study that will allow to find the appropriate design. Otherwise, another attempt will be made to increase the maximum lift coefficient in order to provide the vehicle with a greater mass for the same Speed or, on the contrary, in order to reduce the Stall Speed with a specific mass. For these purposes, XFLR5 and computational fluid dynamics will be used during the development of the paper.[VL] L’estudi de l’aerodinàmica a baix nombre de Reynolds és fonamental degut a l’auge del vehicles aeris no tripulats que volen en aquest règim, cada vegada més emprats pels avantatges que suposen. El principal problema que s’estudiarà consisteix en l’aparició de bambolles de separació laminar, on el flux es desprén de la superfície del perfil per a després tornar a adherirse, modificant així el comportament aerodinàmic. Amb la finalitat d’evitar aquest fenomen, s’estableix com objectiu evitar el despreniment de la corrent amb la incorporació de succió i ejecció. Aleshores, per a cuatre nombres de Reynolds diferents, es tractarà d’evitar l’aparició de la LSB per tal d’augmentar l’eficiència aerodinàmica durant el vol creuer a partir d’un estudi paramètric que permeta trobar el disseny òptim. També es tractarà d’incrementar el coeficient de sustentació màxim per tal que es puga afegir més massa al vehicle per a una mateixa velocitat o, pel contrari, aconseguir que es necessite menys velocitat per a mantindre el vol amb una massa concreta. Per al desenvolupament del treball, s’emprarà XFLR5 i dinàmica de fluids computacional per al corresponent desenvolupament del treball.Romero Pérez, M. (2020). Sobre la mitigación de la separación de la corriente en perfiles aerodinámicos a bajo número de Reynolds. http://hdl.handle.net/10251/151180TFG
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Sobre la mitigación de la separación de la corriente en perfiles aerodinámicos a bajo número de Reynolds
2020Co-Authors: Romero Pérez MaríaAbstract:[ES] El estudio de la aerodinámica a bajo número de Reynolds resulta fundamental debido al auge de las pequeñas aeronaves no tripuladas que vuelan a dicho régimen, cada vez más empleadas por las ventajas que suponen. El principal fenómeno que se estudiará consiste en la aparición de burbujas de separación laminar, producidas cuando el flujo se desprende de la superficie del perfil para después volver a adherirse, modificando así su actuación aerodinámica. Con tal de evitar la aparición de esta burbuja, se fija como objetivo mitigar la separación de la corriente a través de la incorporación de succión y eyección en el perfil estudiado. De este modo y abarcando cuatro números de Reynolds distintos, se tratará de aumentar la eficiencia aerodinámica durante el vuelo de crucero a partir de un estudio paramétrico que permita encontrar el diseño óptimo. Por otro lado, se buscará incrementar el coeficiente de sustentación máximo con tal de poder dotar al vehículo de una mayor masa de despegue para cierta velocidad o, por el contrario, reducir la velocidad de entrada en pérdida para una masa concreta. Con estos objetivos en mente, se empleará el programa XFLR5 y la dinámica de fluidos computacional para el correspondiente desarrollo del trabajo.[EN] The study of low Reynolds number aerodynamics is essencial due to the rise of small unmanned aerial vehicles flying under this regime, increasingly used for the advantages they represent. The main phenomenon that is studied in this paper is the appearance of laminar separation bubbles (LSB), where the flow detaches from the profile surface and then it adheres again, causing the modification of its aerodynamic performance. In order to avoid the appearance of this bubble, the objective is to mitigate the separation of the stream with the incorporation of suction and ejection in the studied profile. Using four different Reynolds numbers, an attempt will be made to increase aerodynamic efficiency during cruise from a parametric study that will allow to find the appropriate design. Otherwise, another attempt will be made to increase the maximum lift coefficient in order to provide the vehicle with a greater mass for the same Speed or, on the contrary, in order to reduce the Stall Speed with a specific mass. For these purposes, XFLR5 and computational fluid dynamics will be used during the development of the paper.[CA] L’estudi de l’aerodinàmica a baix nombre de Reynolds és fonamental degut a l’auge del vehicles aeris no tripulats que volen en aquest règim, cada vegada més emprats pels avantatges que suposen. El principal problema que s’estudiarà consisteix en l’aparició de bambolles de separació laminar, on el flux es desprén de la superfície del perfil per a després tornar a adherirse, modificant així el comportament aerodinàmic. Amb la finalitat d’evitar aquest fenomen, s’estableix com objectiu evitar el despreniment de la corrent amb la incorporació de succió i ejecció. Aleshores, per a cuatre nombres de Reynolds diferents, es tractarà d’evitar l’aparició de la LSB per tal d’augmentar l’eficiència aerodinàmica durant el vol creuer a partir d’un estudi paramètric que permeta trobar el disseny òptim. També es tractarà d’incrementar el coeficient de sustentació màxim per tal que es puga afegir més massa al vehicle per a una mateixa velocitat o, pel contrari, aconseguir que es necessite menys velocitat per a mantindre el vol amb una massa concreta. Per al desenvolupament del treball, s’emprarà XFLR5 i dinàmica de fluids computacional per al corresponent desenvolupament del treball.Romero Pérez, M. (2020). Sobre la mitigación de la separación de la corriente en perfiles aerodinámicos a bajo número de Reynolds. Universitat Politècnica de València. http://hdl.handle.net/10251/151180TFG
Pierluigi Della Vecchia - One of the best experts on this subject based on the ideXlab platform.
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flight tests performances and flight certification of a twin engine light aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate Stall tests have been performed in all configurations and influence of both entry-rate and load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification.
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Flight Tests, Performances and Flight Certification of a Twin-Engine Light Aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate Stall tests have been performed in all configurations and influence of both entry-rate and load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification.
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Flight tests, performances, and flight certification of a twin-engine light aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight-test activities performed on the P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of the P2006T for the normal category under European regulation CS-23. All the acquired data and flight results presented have been focused on both aircraft certification and aircraft performance, stability, and flight quality measurements. The data have been acquired through light, accurate, and reliable flight instrumentation available at the University of Naples “Federico II” department of aerospace engineering. Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics, and ground performances (takeoff and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances in one-engine inoperative conditions. Accurate Stall tests have been performed in all configurations, and the influence of both the entry rate and the load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short takeoff and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS-23 certification
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Flight tests of a twin-engine aircraft: performances, stability and parameter estimation
2009Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:The present paper deals with flight test activities performed on P2006T twin-engine light aircraft recently designed and produced by Tecnam(www.tecnam.com). Research activities and flight tests have been performed during the flight certification (C.S. 23) of P2006 aircraft. All the acquired data and flight results presented have been focused to both aircraft certification and to measure and optimize aircraft performances and flight qualities. All flight data have been acquired through a light, accurate and reliable flight instrumentation avail-able at DIAS(Department of Aerospace Engineering). The first part of the paper deals with flight tests that have been performed to measure and acquire aircraft flight performances. Some flight data about aircraft levelled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglet have been designed and added to the final configuration to obtain good climb performances also in OEI(One Engine Inoperative) condition. Excellent ground performances have been measured with short take-off and landing distances compared to aircraft belonging to the same category. All measured flight performances can be considered very good for this air-craft category and have been used to demonstrate aircraft safety and to obtain C.S. 23 certifi-cation. The second part of the paper deals with flight test activities that have been performed to obtain a quantitative measurement of aircraft flight qualities (i.e. dynamic longitudinal stability characteristics) and to perform a complete aircraft parameter estimation. Through a dedicated set of performed manoeuvres and consequent acquired flight data the longitudinal stability derivatives have been estimated through MLM (maximum likelihood method). A mat-lab code with the longitudinal equation of motion and with classical aircraft dynamics equa-tions has been used to reconstruct the aircraft aerodynamic model
Fabrizio Nicolosi - One of the best experts on this subject based on the ideXlab platform.
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flight tests performances and flight certification of a twin engine light aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate Stall tests have been performed in all configurations and influence of both entry-rate and load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification.
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Flight Tests, Performances and Flight Certification of a Twin-Engine Light Aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate Stall tests have been performed in all configurations and influence of both entry-rate and load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification.
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Flight tests, performances, and flight certification of a twin-engine light aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight-test activities performed on the P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of the P2006T for the normal category under European regulation CS-23. All the acquired data and flight results presented have been focused on both aircraft certification and aircraft performance, stability, and flight quality measurements. The data have been acquired through light, accurate, and reliable flight instrumentation available at the University of Naples “Federico II” department of aerospace engineering. Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics, and ground performances (takeoff and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances in one-engine inoperative conditions. Accurate Stall tests have been performed in all configurations, and the influence of both the entry rate and the load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short takeoff and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS-23 certification
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Flight tests of a twin-engine aircraft: performances, stability and parameter estimation
2009Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:The present paper deals with flight test activities performed on P2006T twin-engine light aircraft recently designed and produced by Tecnam(www.tecnam.com). Research activities and flight tests have been performed during the flight certification (C.S. 23) of P2006 aircraft. All the acquired data and flight results presented have been focused to both aircraft certification and to measure and optimize aircraft performances and flight qualities. All flight data have been acquired through a light, accurate and reliable flight instrumentation avail-able at DIAS(Department of Aerospace Engineering). The first part of the paper deals with flight tests that have been performed to measure and acquire aircraft flight performances. Some flight data about aircraft levelled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglet have been designed and added to the final configuration to obtain good climb performances also in OEI(One Engine Inoperative) condition. Excellent ground performances have been measured with short take-off and landing distances compared to aircraft belonging to the same category. All measured flight performances can be considered very good for this air-craft category and have been used to demonstrate aircraft safety and to obtain C.S. 23 certifi-cation. The second part of the paper deals with flight test activities that have been performed to obtain a quantitative measurement of aircraft flight qualities (i.e. dynamic longitudinal stability characteristics) and to perform a complete aircraft parameter estimation. Through a dedicated set of performed manoeuvres and consequent acquired flight data the longitudinal stability derivatives have been estimated through MLM (maximum likelihood method). A mat-lab code with the longitudinal equation of motion and with classical aircraft dynamics equa-tions has been used to reconstruct the aircraft aerodynamic model
Agostino De Marco - One of the best experts on this subject based on the ideXlab platform.
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flight tests performances and flight certification of a twin engine light aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate Stall tests have been performed in all configurations and influence of both entry-rate and load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification.
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Flight Tests, Performances and Flight Certification of a Twin-Engine Light Aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate Stall tests have been performed in all configurations and influence of both entry-rate and load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification.
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Flight tests, performances, and flight certification of a twin-engine light aircraft
2011Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:This paper deals with flight-test activities performed on the P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of the P2006T for the normal category under European regulation CS-23. All the acquired data and flight results presented have been focused on both aircraft certification and aircraft performance, stability, and flight quality measurements. The data have been acquired through light, accurate, and reliable flight instrumentation available at the University of Naples “Federico II” department of aerospace engineering. Some flight data about aircraft leveled Speed, Stall Speed, climb characteristics, and ground performances (takeoff and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances in one-engine inoperative conditions. Accurate Stall tests have been performed in all configurations, and the influence of both the entry rate and the load factor on Stall Speed have been highlighted. Excellent ground performances have been measured with short takeoff and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS-23 certification
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Flight tests of a twin-engine aircraft: performances, stability and parameter estimation
2009Co-Authors: Fabrizio Nicolosi, Agostino De Marco, Pierluigi Della VecchiaAbstract:The present paper deals with flight test activities performed on P2006T twin-engine light aircraft recently designed and produced by Tecnam(www.tecnam.com). Research activities and flight tests have been performed during the flight certification (C.S. 23) of P2006 aircraft. All the acquired data and flight results presented have been focused to both aircraft certification and to measure and optimize aircraft performances and flight qualities. All flight data have been acquired through a light, accurate and reliable flight instrumentation avail-able at DIAS(Department of Aerospace Engineering). The first part of the paper deals with flight tests that have been performed to measure and acquire aircraft flight performances. Some flight data about aircraft levelled Speed, Stall Speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglet have been designed and added to the final configuration to obtain good climb performances also in OEI(One Engine Inoperative) condition. Excellent ground performances have been measured with short take-off and landing distances compared to aircraft belonging to the same category. All measured flight performances can be considered very good for this air-craft category and have been used to demonstrate aircraft safety and to obtain C.S. 23 certifi-cation. The second part of the paper deals with flight test activities that have been performed to obtain a quantitative measurement of aircraft flight qualities (i.e. dynamic longitudinal stability characteristics) and to perform a complete aircraft parameter estimation. Through a dedicated set of performed manoeuvres and consequent acquired flight data the longitudinal stability derivatives have been estimated through MLM (maximum likelihood method). A mat-lab code with the longitudinal equation of motion and with classical aircraft dynamics equa-tions has been used to reconstruct the aircraft aerodynamic model
Paul Diggle - One of the best experts on this subject based on the ideXlab platform.
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Stall Speed and escape velocity empty metaphors or empirical realities
2020Co-Authors: Luke Bartholomew, Paul DiggleAbstract:'Stall Speed' and 'escape velocity' are commonly heard but often vaguely defined physics metaphors used to describe apparent business cycle dynamics. Using GDP data for the OECD economies, we find evidence for the existence of a weak and a strong form of Stall Speed in the majority of these economies, but reject weak and strong form escape velocity everywhere. Specifically, we find higher probabilities of recession following periods of low growth, including non-linear increases in these probabilities around certain thresholds; but no equivalent decrease in recession probabilities after periods of high growth. We then employ Markov switching models as a secondary technique to test for distinct business cycle phases that might equate to Stalls and escapes. This analysis rarely picks out Stall Speed and escape velocity as separate business cycle regimes, and instead points to a broader and more idiosyncratic suite of regimes rooted in individual economies' economic history. Taken together, these results suggest that Stall Speed dynamics are present in the GDP data generating process for many OECD economies, but they are not a strong enough feature to emerge as a defining characteristic of the business cycle. Our findings caution against the overuse of the Stall Speed and escape velocity metaphors in a macroeconomic context.
