The influence of in-flight conditions on the community noise of propeller-driven aircraft is studied.The problem of converting the noise levels of light propeller aircraft obtained from measurements under static condi...The influence of in-flight conditions on the community noise of propeller-driven aircraft is studied.The problem of converting the noise levels of light propeller aircraft obtained from measurements under static conditions to real flight conditions is considered.The acoustic characteristics of AN-2,YAK-18T and MAI-223M aircrafts measured under static conditions in the far field and during level flights are compared.It is found that the noise levels in the area of low and medium frequencies up to 400–630 Hz in the 1/3-octave frequency bands are determined by the acoustic radiation of the power plant and can be recalculated from the results of noise measurements of power plants under static conditions with sufficient accuracy to solve engineering problems.At frequencies above 400–630 Hz,the airframe noise becomes significant.At the same time,up to the frequency of the first tone of the propeller noise,the measured noise levels,depending on the wind speed,can be determined by ambient noise.展开更多
The results of an experimental study of wall pressure fluctuations field in a turbulent boundary layer on the surface of the fuselage of a Superjet 100 aircraft for three characteristic fuselage zones-the nose,center ...The results of an experimental study of wall pressure fluctuations field in a turbulent boundary layer on the surface of the fuselage of a Superjet 100 aircraft for three characteristic fuselage zones-the nose,center section,and rear section are presented.The method of conducting the experiment and processing the measurement results is described.The effect of the airspeed(flight Mach number)on the spectral levels of pressure fluctuations is considered.The forms of pressure fluctuations spectrum are consistent with the results of studies by other authors,and semiempirical models,describing the Robertson/Cockburn and Robertson models,respectively,the Efimtsov/Rackle and Weston models.The effect of the jet on the levels of pressure fluctuations in the rear fuselage of the cabin is estimated.It is shown that the engine jet cannot be a significant noise source in the cabin of a Superjet 100.展开更多
The article considers the scheme of performing computational studies in the design of propeller-driven aircraft,taking into account the required acoustic characteristics.Within the framework of this work,the analysis ...The article considers the scheme of performing computational studies in the design of propeller-driven aircraft,taking into account the required acoustic characteristics.Within the framework of this work,the analysis of the influence of the use of electric power plant on the light propeller-driven aircraft noise is carried out on the basis of available publications and author’s research.Two light propeller-driven aircraft Extra 330 and Magnus Fusion 212 were considered,for which flight acoustic tests were performed with a standard piston power plant and an electric one to determine the effect of the use of electric motors on the light propeller-driven aircraft noise community noise levels.Thus,when using hybrid and electric power plant,there will be a significant transformation of the sound field of light propeller-driven aircraft noise and unmanned aerial vehicle.It is worth expecting the dominance of propeller noise(for take-off power condition of the power plant)with a significant influence of installation effects and airframe noise.When flying an aircraft at relatively low altitudes with low speeds,the effect of using electric and hybrid power plant may be insignificant.At the same time,when flying at altitudes from 100 m,one should expect a decrease in the degree of audibility of unmanned aerial vehicle with electric power plants compared to piston ones,due to the significant attenuation of high-frequency noise of electric engines with increasing distance to the aircraft.展开更多
The results of a study of the acoustic characteristics of an aviation opposed piston engine are presented.The tests were carried out during the run of the power plants of the light propeller-driven aircraft F30,MAI-22...The results of a study of the acoustic characteristics of an aviation opposed piston engine are presented.The tests were carried out during the run of the power plants of the light propeller-driven aircraft F30,MAI-223M and MAI-890U under static conditions at the local aerodrome of Moscow Aviation Institute(National Research University).The influence of cowling on the energy characteristics of the sound field of the engine is considered.The influence of the engine power condition on the directivity of the tonal components of its radiation is studied.The dependences of the sound power on engine speed are obtained.展开更多
This paper presents a fast way to predict the noise level of installed propeller on wing.Installing the propeller on wing has not only increased wing lift coefficient,but also greatly changed the noise direction.Howev...This paper presents a fast way to predict the noise level of installed propeller on wing.Installing the propeller on wing has not only increased wing lift coefficient,but also greatly changed the noise direction.However,the precise prediction of noise level is a difficult and cumbersome,since the aerodynamic interaction effects are so complicated.But with a series of simplicity,here still can get a concise formulation,which is sufficient to evaluate the noise level of early design of propeller-driven aircraft.展开更多
文摘The influence of in-flight conditions on the community noise of propeller-driven aircraft is studied.The problem of converting the noise levels of light propeller aircraft obtained from measurements under static conditions to real flight conditions is considered.The acoustic characteristics of AN-2,YAK-18T and MAI-223M aircrafts measured under static conditions in the far field and during level flights are compared.It is found that the noise levels in the area of low and medium frequencies up to 400–630 Hz in the 1/3-octave frequency bands are determined by the acoustic radiation of the power plant and can be recalculated from the results of noise measurements of power plants under static conditions with sufficient accuracy to solve engineering problems.At frequencies above 400–630 Hz,the airframe noise becomes significant.At the same time,up to the frequency of the first tone of the propeller noise,the measured noise levels,depending on the wind speed,can be determined by ambient noise.
文摘The results of an experimental study of wall pressure fluctuations field in a turbulent boundary layer on the surface of the fuselage of a Superjet 100 aircraft for three characteristic fuselage zones-the nose,center section,and rear section are presented.The method of conducting the experiment and processing the measurement results is described.The effect of the airspeed(flight Mach number)on the spectral levels of pressure fluctuations is considered.The forms of pressure fluctuations spectrum are consistent with the results of studies by other authors,and semiempirical models,describing the Robertson/Cockburn and Robertson models,respectively,the Efimtsov/Rackle and Weston models.The effect of the jet on the levels of pressure fluctuations in the rear fuselage of the cabin is estimated.It is shown that the engine jet cannot be a significant noise source in the cabin of a Superjet 100.
文摘The article considers the scheme of performing computational studies in the design of propeller-driven aircraft,taking into account the required acoustic characteristics.Within the framework of this work,the analysis of the influence of the use of electric power plant on the light propeller-driven aircraft noise is carried out on the basis of available publications and author’s research.Two light propeller-driven aircraft Extra 330 and Magnus Fusion 212 were considered,for which flight acoustic tests were performed with a standard piston power plant and an electric one to determine the effect of the use of electric motors on the light propeller-driven aircraft noise community noise levels.Thus,when using hybrid and electric power plant,there will be a significant transformation of the sound field of light propeller-driven aircraft noise and unmanned aerial vehicle.It is worth expecting the dominance of propeller noise(for take-off power condition of the power plant)with a significant influence of installation effects and airframe noise.When flying an aircraft at relatively low altitudes with low speeds,the effect of using electric and hybrid power plant may be insignificant.At the same time,when flying at altitudes from 100 m,one should expect a decrease in the degree of audibility of unmanned aerial vehicle with electric power plants compared to piston ones,due to the significant attenuation of high-frequency noise of electric engines with increasing distance to the aircraft.
文摘The results of a study of the acoustic characteristics of an aviation opposed piston engine are presented.The tests were carried out during the run of the power plants of the light propeller-driven aircraft F30,MAI-223M and MAI-890U under static conditions at the local aerodrome of Moscow Aviation Institute(National Research University).The influence of cowling on the energy characteristics of the sound field of the engine is considered.The influence of the engine power condition on the directivity of the tonal components of its radiation is studied.The dependences of the sound power on engine speed are obtained.
文摘This paper presents a fast way to predict the noise level of installed propeller on wing.Installing the propeller on wing has not only increased wing lift coefficient,but also greatly changed the noise direction.However,the precise prediction of noise level is a difficult and cumbersome,since the aerodynamic interaction effects are so complicated.But with a series of simplicity,here still can get a concise formulation,which is sufficient to evaluate the noise level of early design of propeller-driven aircraft.
