Oleksandr Zaporozhets

Aircraft Noise: Assessment, prediction and Control

A review of the aircraft noise problem Environmental impacts of airports Description of aircraft noise Basic equations Criteria and methods of aircraft noise assessment Control of noise impact Regulations and standards for aircraft noise The main sources of aircraft noise Jet noise Fan and turbine noise Combustion chamber noise Airframe noise Propeller and helicopter noise Aircraft noise propagation Factors influencing outdoor sound Predicting the ground effect Comparisons of measured and predicted ground effects Shadow zones Classification of meteorological effects Typical sound speed profiles Sound propagation in a turbulent atmosphere Sound propagation over noise barriers Sound propagation through trees Methods for aircraft noise prediction Introduction An acoustic model of an aircraft Evaluation of an acoustic model of an aircraft Prediction of noise under the flight path: trajectory models Effects of ground, atmosphere and shielding by wing and fuselage Prediction of aircraft noise during ground operations Prediction of noise in the vicinity of an airport The influence of operational factors on aircraft noise levels Aircraft on the ground Under the flight path Takeoff and climbing Descent and landing Methods of aircraft noise reduction Reduction of noise at source Noise reduction under the flight path Noise reduction in the vicinity of an airport The efficiency of acoustic screens for reducing noise from airport ground operations Reduction of noise impact by optimum scheduling of aircraft operations Monitoring of aircraft noise Reasons for noise monitoring Instrumentation for aircraft noise monitoring Uncertainties in measurements and predictions Identifying sources of noise events Interdependencies and tradeoffs between noise and other environmental factors associated with civil aviation

Passive acoustic radar for aircraft trajectory tracking

In this paper the algorithm of signal detection for passive acoustic radar is proposed. This algorithm is based on processing of multiple input signals, which are received from several acoustic aerials with some number of microphones in each of them. For the signal processing the original algorithm of calculation of wide-band ambiguity function together with its projection on time axis is used. The suggested algorithm is proposed to use for measuring of aircraft noise with the aim of environmental protection.

Signal processing in passive acoustic location for aircraft detection

This paper is connected with the development and application of special algorithm of digital signal processing for passive acoustic location using cheap equipment. The calculation of ambiguity function by spectral method is suggested instead of classical integration. The effectiveness of location is proved by full-scale experiments.

Algorithm of Passive Acoustic Locator Data Processing for Flying Vehicle Detection and Tracking

This paper deals with the development of the special algorithm of digital signal processing, which allows to detect flying vehicles and define their coordinates and radial velocity. The coordinates are used for trajectory tracking. The velocity is useful to distinguish maneuvering objects. Detection of an object is based on calculation of ambiguity function. It is proposed to do it by spectral method instead of classical integration. This is one of advantages of the developed algorithm.

Improvement of Airport Local Air Quality Modeling

Even with all the benefits an airports brings, it may produce significant impacts on those living nearby and on the environment. Lately, interest in this problem has intensified in connection with ...

Operational conditions influence on aircraft engine emission and pollution inside the airport

Determination of emission indexes under real operational and meteorological conditions is actual task, as input data for models and high accurate assessment of aircraft emissions contribution to total air pollution in the vicinity of airport. Also estimation emission indexes with taking into account engine age and its maintenance allow to calculate precisely the emission inventories of airports. Analysis results of emission measurement data for aircraft engine concluded that method, which takes into account the influence of the real operational (fuel flow rate, operation period of engine/age and its maintenance) and ambient temperature on emission indices allow to get more precisely results of emission inventory of aircraft engines.

Викиди зважених часток від повітряних суден під час експлуатації в межах аеропорту

Purpose : The effects of aircraft engine emissions within the planetary boundary layer under the landing/ take-off operations contribute sufficiently to deterioration of air pollution in the vicinity of the airports and nearby residential areas. Currently the primary object of airport air quality are the nitrogen oxides and particle matter (PM 10 , PM 2.5 and ultrafine PM) emissions from aircraft engine exhausts as initiators of photochemical smog and regional haze, which may further impact on human health. Analysis of PM emission inventory results at major European airports highlighted on sufficiently high contribution of aircraft engines and APU. The paper aims to summarize the knowledge on particle size distributions, particle effective density, morphology and internal structure of aircraft PM, these properties are critical for understanding of the fate and potential health impact of PM. It also aims to describe the basic methods for calculation of emission and dispersion of PM, produced by aircrafts under the LTO operations. Methods : analytical solution of the atmospheric diffusion equation is used to calculate the maximum PM concentration from point emission source. The PM concentration varies inversely proportional to the wind velocity u 1 and directly proportional to the vertical component of the turbulent exchange coefficient k 1 /u 1 . The evaluation of non-volatile PM concentration includes the size and shape of PM. PolEmiCa calculates the distributions of PM fractions for aircraft and APU exhausts (height of installation was given H=4,5m like for Tupolev-154). Results: The maximum concentration of PM in exhaust from APU is higher and appropriate distance is less than in case for gas. PM polydispersity leads to the separation of maximums concentration in space for individual fractions on the wind direction and therefore it contributes to the reduction of maximum total concentration. Discussion : But although the APU has contributed significantly to the emission of aircraft at airports, APU emissions are not certificated by ICAO or any other responsible for that authority. It is quite actual task for local air quality to development model and find measurement techniques to identify aircraft engine and APU contribution to total airport PM pollution.

Моделювання та вимірювання концентрацій NOx у струмені газів від авіадвигуна за експлуатаційних умов на території аеродрому

Purpose : Airport air pollution is growing concern because of the air traffic expansion over the years (at annual rate of 5 %), rising tension of airports and growing cities expansion close each other (for such Ukrainian airports, as Zhulyany, Boryspol, Lviv, Odesa and Zaporizhzhia) and accordingly growing public concern with air quality around the airport. Analysis of inventory emission results at major European and Ukrainian airports highlighted, that an aircraft is the dominant source of air pollution in most cases under consideration. For accurate assessment of aircraft emission contribution to total airport pollution and development of successful mitigation strategies, it is necessary to combine the modeling and measurement methods. Methods : Measurement of NO x concentration in the jet/plume from aircraft engine was implemented by chemiluminescence method under real operating conditions (taxi, landing, accelerating on the runway and take-off) at International Boryspol airport (IBA). Modeling of NO x concentration was done by complex model PolEmiCa, which takes into account the transport and dilution of air contaminates by exhaust gases jet and the wing trailing vortexes. Results : The results of the measured NO x concentration in plume from aircraft engine for take-off conditions at IBA were used for improvement and validation of the complex model PolEmiCa. The comparison of measured and modeled instantaneous concentration of NO x was sufficiently improved by taking into account the impact of wing trailing vortices on the parameters of the jet (buoyancy height, horizontal and vertical deviation) and on concentration distribution in plume . Discussion : Combined approach of modeling and measurement methods provides more accurate representation of aircraft emission contribution to total air pollution in airport area. Modeling side provides scientific grounding for organization of instrumental monitoring of aircraft engine emissions, particularly, scheme for disposition the monitoring stations with aim to detect maximum concentration which is characterized for jets/plumes from aircraft engines.

Estimation of buoyancy effect and penetration length of jet from aircraft engine by large eddy simulation method

Emission inventories analysis at major European and Ukrainian airports highlighted that aircraft is a dominant source of air pollution. To evaluate the aircraft contribution in airport air quality it is important to take in mind some features of the aircraft, as special source of air pollution. The most part of landing-take-off cycle the aircraft is manoeuvring on the ground, it is subjected to fluid flow that can create a strong vortex between the ground and engine nozzle, which have essential influence on structure and basic mechanisms (Coanda and buoyancy effects) of exhaust gases jet from aircraft engine. To evaluate the influence of the ground on jets parameters (height and longitudinal coordinate of buoyancy effect, length of jet penetration), the numerical simulation of wall jet by Fluent 6.3 implemented for different combination of initial jet velocity and height of engine installation. Obtained results of numerical simulations provide improvement of model PolEmiCa.

Moving target detection and tracking using passive acoustic radar

The moving target detection and tracking method for passive radars is investigated. The original algorithm, which is based on the wideband ambiguity function calculation, is suggested. The effectiveness of the suggested algorithm is proved by experimental measurements.