scholarly journals Ambient Temperature and Pressure Corrections for Aircraft Gas Turbine Idle Pollutant Emissions

1976 ◽  
Author(s):  
J. W. Marzeski ◽  
W. S. Blazowski
Keyword(s):  
Ambient Temperature ◽  
Ambient Pressure ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Emission Model ◽  
Correction Factors ◽  
Ambient Conditions ◽  
Temperature And Pressure

Recent investigations have indicated that aircraft engine exhaust emissions are sensitive to ambient conditions. This paper reports on combustor rig testing intended to evaluate variations due to ambient temperature and pressure with special emphasis on idle engine operating conditions. Empirically determined CO, CxHy, and NOx correction factors — the ratio of the pollutant emission index value obtained during standard day operation to that resulting during actual ambient conditions — are presented. The effects of engine idle cycle pressure ratio, primary zone fuel-air ratio, and fuel type were investigated. Ambient temperature variations were seen to cause substantial emission changes; correction factors in excess of 2.0 were determined in some cases. Ambient pressure variations were found to be less substantial. A previously published NOx emission model and a simplified hydrocarbon combustion analysis are shown to be in general agreement with the empirical results.

The Effects of Ambient Conditions on Gas Turbine Emissions—Generalized Correction Factors

1978 ◽  
Vol 100 (4) ◽  
pp. 640-646 ◽  
Author(s):  
P. Donovan ◽  
T. Cackette
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Gas Turbine Engines ◽  
Correction Factors ◽  
Oxides Of Nitrogen ◽  
Ambient Conditions ◽  
Nitrogen Emission ◽  
Wide Range

A set of factors which reduces the variability due to ambient conditions of the hydrocarbon, carbon monoxide, and oxides of nitrogen emission indices has been developed. These factors can be used to correct an emission index to reference day ambient conditions. The correction factors, which vary with engine rated pressure ratio for NOx and idle pressure ratio for HC and CO, can be applied to a wide range of current technology gas turbine engines. The factors are a function of only the combustor inlet temperature and ambient humidity.

Modelling Strategies for Large-Eddy Simulation of Lean Burn Spray Flames

2017 ◽  
Author(s):  
S. Puggelli ◽  
D. Bertini ◽  
L. Mazzei ◽  
A. Andreini
Keyword(s):  
Large Eddy Simulation ◽  
Ambient Pressure ◽  
Nox Reduction ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Lean Burn ◽  
Eddy Simulation ◽  
Flamelet Generated Manifold ◽  
Large Eddy ◽  
Modelling Strategies

During the last years aero-engines are progressively evolving toward design concepts that permit improvements in terms of engine safety, fuel economy and pollutant emissions. With the aim of satisfying the strict NOx reduction targets imposed by ICAO-CAEP, lean burn technology is one of the most promising solutions even if it must face safety concerns and technical issues. Hence a depth insight on lean burn combustion is required and Computational Fluid Dynamics (CFD) can be a useful tool for this purpose. In this work a comparison in Large-Eddy Simulation (LES) framework of two widely employed combustion approaches like the Artificially Thickened Flame (ATF) and the Flamelet Generated Manifold (FGM) is performed using ANSYS® Fluent v16.2. Two literature test cases with increasing complexity in terms of geometry, flow field and operating conditions are considered. Firstly, capabilities of FGM are evaluated on a single swirler burner operating at ambient pressure with a standard pressure atomizer for spray injection. Then a second test case, operated at 4 bar, is simulated. Here kerosene fuel is burned after an injection through a prefilming airblast atomizer within a co-rotating double swirler. Obtained comparisons with experimental results show the different capabilities of ATF and FGM in modelling the partially-premixed behaviour of the flame and provides an overview of the main strengths and limitations of the modelling strategies under investigation.

scholarly journals Test campaign of a ducted wind turbine in real operating conditions

2019 ◽  
Vol 113 ◽  
pp. 03005
Author(s):  
Enrico Valditerra ◽  
Massimo Rivarolo ◽  
Aristide F. Massardo ◽  
Marco Gualco
Keyword(s):  
Wind Turbine ◽  
Urban Areas ◽  
Energy Production ◽  
Electrical Energy ◽  
Clean Energy ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Ambient Conditions ◽  
Wind Speeds ◽  
Electrical Energy Production

Wind turbine installation worldwide has increased at unrested pace, as it represents a 100% clean energy with zero CO2 and pollutant emissions. However, visual and acoustic impact of wind turbines is still a drawback, in particular in urban areas. This paper focuses on the performance evaluation of an innovative horizontal axis ducted wind turbine, installed in the harbour of Genova (Italy) in 2018: the turbine was designed in order to minimize visual and acoustic impacts and maximize electrical energy production, also during low wind speed periods. The preliminary study and experimental analyses, performed by the authors in a previous study, showed promising results in terms of energy production, compared to a traditional generator ( factor >2.5 on power output). In the present paper, the test campaign on a scaled-up prototype, installed in the urban area of Genova, is performed, with a twofold objective: (i) comparison of the ducted innovative turbine with a standard one, in order to verify the increase in energy production; (ii) analysis of the innovative turbine for different wind speeds and directions, evaluating the influence of ambient conditions on performance. Finally, based on the obtained results, an improved setup is proposed for the ducted wind turbine, in order to further increase energy production mitigating its visual impact.

Spray dynamics simulations for pulsatile injection at different ambient pressure and temperature conditions

2019 ◽  
Vol 234 (4) ◽  
pp. 500-519
Author(s):  
Anandteerth Muddapur ◽  
Sahu Srikrishna ◽  
T Sundararajan
Keyword(s):  
Numerical Study ◽  
Ambient Pressure ◽  
Operating Conditions ◽  
Discrete Phase Model ◽  
Ambient Conditions ◽  
Fuel Temperature ◽  
Shape Distortion ◽  
Penetration Length ◽  
Droplet Shape ◽  
System Pressure

A numerical study on the transient characteristics of a pulsatile, iso-octane spray issuing from a pressure-swirl atomizer is presented. The effects of system pressure and temperature, as well as the initial fuel temperature on spray dispersion and evaporation, are highlighted. The computations were carried out using ANSYS FLUENT-15.0, assuming the spray dispersion to be axisymmetric. Gas phase turbulence is simulated using the renormalized group k- ε model, while the discrete phase model is used for tracking fuel droplets. The linear instability sheet atomization model is adopted for the primary breakup of the liquid sheet, and the Taylor Analogy Breakup and Wave Breakup models are adopted for the secondary breakup, depending upon the operating conditions. The drag force on the droplet is evaluated, after incorporating the effects of evaporation and neighbouring droplets, along with droplet shape distortion. The significance of droplet collision on the evolution of droplet size distribution is examined. The local mean drop sizes and spray penetration length are in agreement with the experimental results of the literature. The predicted results indicate that the spray is narrower and penetrates less at higher ambient pressure. In this respect, the additional force on droplets due to local static pressure gradient is examined in detail. The effect of ambient conditions on the spray evaporation process is studied based on the spatio-temporal evolution of the equivalence ratio of the mixture of fuel vapour and air.

scholarly journals Development of a Variable Valve Actuation Control to Improve Diesel Oxidation Catalyst Efficiency and Emissions in a Light Duty Diesel Engine

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4561 ◽  
Author(s):  
José R. Serrano ◽  
Francisco J. Arnau ◽  
Jaime Martín ◽  
Ángel Auñón
Keyword(s):  
Diesel Oxidation Catalyst ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Oxidation Catalyst ◽  
Pollutant Emission ◽  
Engine Model ◽  
Light Duty ◽  
Diesel Oxidation ◽  
Variable Valve ◽  
Catalyst Efficiency

Growing interest has arisen to adopt Variable Valve Timing (VVT) technology for automotive engines due to the need to fulfill the pollutant emission regulations. Several VVT strategies, such as the exhaust re-opening and the late exhaust closing, can be used to achieve an increment in the after-treatment upstream temperature by increasing the residual gas amount. In this study, a one-dimensional gas dynamics engine model has been used to simulate several VVT strategies and develop a control system to actuate over the valves timing in order to increase diesel oxidation catalyst efficiency and reduce the exhaust pollutant emissions. A transient operating conditions comparison, taking the Worldwide Harmonized Light-Duty Vehicles Test Cycle (WLTC) as a reference, has been done by analyzing fuel economy, HC and CO pollutant emissions levels. The results conclude that the combination of an early exhaust and a late intake valve events leads to a 20% reduction in CO emissions with a fuel penalty of 6% over the low speed stage of the WLTC, during the warm-up of the oxidation catalyst. The same set-up is able to reduce HC emissions down to 16% and NOx emission by 13%.

Design Considerations of an Airborne Free Piston Compressor

1987 ◽  
Vol 201 (3) ◽  
pp. 177-184 ◽  
Author(s):  
E Sher
Keyword(s):  
Ambient Pressure ◽  
Pressure Ratio ◽  
Combustion Process ◽  
Piston Compressor ◽  
Computer Code ◽  
Thermodynamic Efficiency ◽  
Atmospheric Conditions ◽  
Ambient Conditions ◽  
Free Piston ◽  
Detailed Computer

The effect of the atmospheric conditions on the performance of a spark ignition free piston engine has been investigated. A detailed computer code has been developed to simulate the unit cycle and was used to evaluate the effect of its geometrical proportions and the ambient conditions on the cycle performances. The model includes a semi-empirical model for the scavenging process, calculations of the flows into and out of the cylinders, empirical expressions for the combustion process and a practical approach for the heat transfer. The model has been calibrated by using experimental results of a conventional two-stroke engine having identical cylinder and port assemblies. It was concluded that the thermodynamic efficiency of the unit is strongly dependent on the receiver to the atmospheric pressure ratio, the compression ratio of the compressor, the compressor aspect ratio and the ambient pressure. It was shown that the thermodynamic efficiency varies insignificantly with the ambient temperature.

scholarly journals Efficiency Analysis of the Turbine using Calorific Value Parameters for a 10 Megawatt Gas Turbine

2021 ◽  
pp. 59-66
Author(s):  
Rex K.C Amadi ◽  
Charles David
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pressure Ratio ◽  
Calorific Value ◽  
Operating Conditions ◽  
Outlet Temperature ◽  
Flow Process ◽  
Compressor Work ◽  
Gas Turbine Power Plant

This research is based on the thermodynamic performance of a gas turbine power plant.  It considered the variation of operating conditions, i.e. the ambient temperature, the compressor outlet temperature, pressure ratio, etc. on the performance of the gas turbine thermal efficiency, turbine work, compressor work, etc. which were derived and analyzed.  The Gross (higher) calorific values at constant pressure () heat of combustion in a flow process from state 1 to state 2 was considered and used to analyze our thermal efficiency.  The results show that the ambient temperature and air to fuel ratio strongly influence the turbine work, compressor work and thermal efficiency.  In addition, the thermal efficiency and power decreases linearly with increase of the ambient temperature.  However, the efficiency analyzed when the calorific parameters were considered was higher than the efficiency when the basic thermodynamic theories (first and second law principles) were used.  The first ranges between 31% to 33, while the second ranges between 28% to 32% under the same ambient temperature conditions

The Effect of Ambient Conditions on the Performance of Supplementary Fired Gas-Steam Combined Cycle

2006 ◽  
Author(s):  
M. J. Kermani ◽  
B. Rad Nasab ◽  
M. Saffar-Avval
Keyword(s):  
Power Plant ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Ambient Pressure ◽  
Combined Cycle ◽  
Ambient Conditions ◽  
Site Location ◽  
Steam Generators ◽  
Steam Cycle

The effect of ambient conditions, ambient temperature and site location of the power plant (the altitude or ambient pressure), on the performance of a typical supplementary fired (SF) gas-steam combined cycle (CC) is studied, and its performances are compared with that of the unfired case. The CC used in the present study is comprised of two V94.2 gas turbine units, two HR-steam generators and a single steam cycle. For the cases studied, it is observed that SF can increase the total net power of the CC by 5% and the efficiency for the fired-cycle is observed to be about 1% less than that of unfired-cycle case. The variations of the total net power with ambient temperature for both supplementary fired and unfired cases (slope w.r.t. the ambient temperature) are almost identical.

IMPACTS OF AMBIENT TEMPERATURE AND PRESSURE ON PM2.5 EMISSION PROFILES OF LIGHT-DUTY DIESEL VEHICLES

2012 ◽  
Vol 11 (06) ◽  
pp. 1240037
Author(s):  
CHENYU WANG ◽  
YE WU ◽  
ZHENHUA LI ◽  
JIMING HAO
Keyword(s):  
Ambient Temperature ◽  
Size Distribution ◽  
Ambient Pressure ◽  
Passenger Cars ◽  
Test Range ◽  
Diesel Vehicles ◽  
Light Duty ◽  
Mass Size ◽  
Temperature And Pressure ◽  
The Impact

The impact of the environmental factors on the emissions of particulate matter (PM) number, size distribution and mass size distribution from diesel passenger cars was evaluated. Particle measurements from five modern light-duty diesel vehicles (LDDV) were performed in June and November 2011. Commercial low sulfur diesel fuel (less than 50 ppm) was used during the testing of these vehicles which were not equipped with after-treatment devices. The dynamometer test was based on the Economic Commission of Europe (ECE) 15 cycles. The results indicate that PM2.5 emissions from LDDV are significantly affected by ambient temperature and pressure. A comparison of the emissions concentration of PM2.5 in these two different months showed that the number concentration in June was (3.8 ± 0.69) × 107 cm-3 and (2.5 ± 0.66) × 107 cm-3 in November. The PM concentration of about 30 nm diameter was 25 ± 6% of the total emissions in November while only 14 ± 3% of total emissions in June. In the 60 nm to 2.5 μm test range, November data shows less of a contribution for number than data from June testing. The concentration of mass emissions in June was (325 ± 44) mg/m3 and (92 ± 30) mg/m3 in November. The contribution of the number of PM particles in November testing is lower than testing in June by 34% and the mass concentration in November is 70% lower than that in June. With the decrease of ambient temperature and the increase of ambient pressure, both the oxygen concentration in cylinder and air–fuel ratio are increased, which caused lower particle number and mass emissions during November testing. The size distribution is also altered by these changes: the more efficient in-cylinder combustion resulted in a higher proportion of particles in the 30 nm and smaller range than for other particle sizes.

Temperature and Pressure Measurements in a Hot Cascade With Film Cooled Endwalls and Airfoils

2008 ◽  
Author(s):  
James W. Post ◽  
Sumanta Acharya
Keyword(s):  
Surface Temperature ◽  
Pressure Ratio ◽  
Density Ratio ◽  
Operating Conditions ◽  
Maximum Pressure ◽  
Pressure Measurements ◽  
Suction Surface ◽  
Cooling Effectiveness ◽  
Exit Temperature ◽  
Temperature And Pressure

Measurements of endwall and vane cooling effectiveness are reported in a pressurized hot cascade consisting of a natural-gas-fired combustor and film-cooled guide-vanes and endwall. The experiments are performed for operating conditions that are more realistic than typical low-speed cascade studies. Measurements are reported for a maximum pressure ratio (Po,∞/Ps) of 2, combustor exit temperature of 750 °F (399 °C), blowing ratios in the range of 1–2, and coolant to freestream density ratio (DR) of around 2. Results reported include pressure ratios, surface temperature ratios and cooling effectiveness along the endwall and airfoil surfaces. Cooling effectiveness (non-dimensional surface temperature) values in the range of 0.2–0.3 are generally observed along the endwall with poorer coverage in the vicinity of the suction surface.

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