Experimental and chemical kinetic study of the impact of n-butanol blending on the gross engine performance of a CRDI engine

2018 ◽  
Vol 178 ◽  
pp. 400-414 ◽  
Author(s):  
Anil Bhaurao Wakale ◽  
S. Banerjee ◽  
R. Banerjee
Keyword(s):  
Kinetic Study ◽  
Engine Performance ◽  
Chemical Kinetic ◽  
The Impact

Ozone Production With Plasma Discharge: Comparisons Between Activated Air and Activated Fuel/Air Mixture

2021 ◽  
Author(s):  
Ghazanfar Mehdi ◽  
Maria Grazia De Giorgi ◽  
Donato Fontanarosa ◽  
Sara Bonuso ◽  
Antonio Ficarella
Keyword(s):  
Experimental Data ◽  
Plasma Chemistry ◽  
Kinetic Scheme ◽  
Plasma Discharge ◽  
Chemical Kinetic ◽  
Ozone Production ◽  
Air Plasma ◽  
Flammability Limits ◽  
Combustion Enhancement ◽  
The Impact

Abstract This study focused on the comparative analysis about the production of ozone and active radicals in presence of nanopulsed plasma discharge on air and on fuel/air mixture to investigate its effect on combustion enhancement. This analysis is based on numerical modeling of air and methane/air plasma discharge with different repetition rates (100 Hz, 1000 Hz and 10000 Hz). To this purpose, a two-step approach has been proposed based on two different chemistry solvers: a 0-D plasma chemistry solver (ZDPlasKin toolbox) and a combustion chemistry solver (CHEMKIN software suite). Consequently, a comprehensive chemical kinetic scheme was generated including both plasma excitation reactions and gas phase reactions. Validation of air and methane/air mechanisms was performed with experimental data. Kinetic models of both air and methane/air provides good fitting with experimental data of O atom generation and decay process. ZDPlasKin results were introduced in CHEMKIN in order to analyze combustion enhancement. It was found that the concentrations of O3 and O atom in air are higher than the methane/air activation. However, during the air activation peak concentration of ozone was significantly increased with repetition rates and maximum was observed at 10000 Hz. Furthermore, ignition timings and flammability limits were also improved with air and methane/air activation but the impact of methane/air activation was comparatively higher.

Sensitivity Analysis and Experimental Validation of Transient Performance Predictions for a Short-Range Turbofan

2016 ◽  
Author(s):  
Maria V. Culmone ◽  
Nicolás Garcia-Rosa ◽  
Xavier Carbonneau
Keyword(s):  
Short Range ◽  
Engine Performance ◽  
Sensitivity Study ◽  
Simulation Software ◽  
Tip Clearance ◽  
Mass Storage ◽  
Transient Effects ◽  
Transient Model ◽  
Blade Tip ◽  
The Impact

Transient effects are important features of engine performance calculations. The aim of this paper is to analyze a new, fully transient model implemented using the PRopulsion Object Oriented Simulation Software (PROOSIS) for a civil, short range turbofan engine. A transient turbofan model, including the mechanical inertia effect has been developed in PROOSIS. Specific physical effects such as heat soakage, mass storage, blade tip clearance and combustion delay have been implemented in the relevant components of PROOSIS to obtain a fully transient model. Since a large number of components are concerned by all the transient effects, an influence study is presented to determine which are the most critical effects, and in which components. Inertia represents the relevant phenomenon, followed by thermal effects, combustion delay and finally mass storage. The comparison with experimental data will provide a first validation of the model. Finally a sensitivity study is reported to assess the impact of uncertain knowledge of key input parameters in the response time prediction accuracy.

Application of Simplified Parametric Model to Estimate Fan Blade-Out Response

2018 ◽  
Author(s):  
Theodore S. Brockett ◽  
Jerzy T. Sawicki
Keyword(s):  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Engine Performance ◽  
Low Pressure ◽  
External Loading ◽  
System Response ◽  
Angular Rotation ◽  
Mass Eccentricity ◽  
Fan Blade ◽  
The Impact

A six-degree-of-freedom non-linear model is developed using Lagrange’s equation. The model is used to estimate transient fan-stage dynamic response during a fan-blade-out event in a turbo fan engine. The coupled degrees of freedom in the model include the fan whirl in the fan plane, the torsional response of the fan and low-pressure turbines (LPTs) about the engine centerline, the radial position of the released blade fragment, and the angular rotation of the trailing blade from its free state due to acceleration of the released blade. The released blade is assumed to slide radially outward along the trailing blade without friction. The external loading applied to the system includes fan imbalance, the remaining fan blades machining away the rub strip, rubbing of the blades with the fan case, and slowly-varying torques on the low pressure (LP) spool as engine performance degrades. The machining of the abradable imparts tangential loading on the fan blades as momentum is transferred to the liberated rub strip material. After application of the initial conditions including angular positions, angular velocities, released blade fragment position, and torsional wind-up, the governing equations are integrated forward in time from the instant the blade fragment is released. A reasonable match to test data is shown. Parameters affecting the fan-system response are varied to study the impact on fan peak lateral whirl amplitude, peak LP shaft torque, and peak loading on the trailing blade. It is found that the rub strip and mass eccentricity have the strongest influence on the LP shaft torsional loading. It is found that mass eccentricity has the largest influence on peak fan whirl. It is also found that released blade mass and attachment stiffness have the largest influence on the trailing blade loading.

scholarly journals Preliminary Design Framework for the Power Gearbox in a Contra-Rotating Open Rotor

2020 ◽  
Author(s):  
Diana G. San Benito Pastor ◽  
Devaiah Nalianda ◽  
Vishal Sethi ◽  
Ron Midgley ◽  
Andrew Rolt ◽  
...  
Keyword(s):  
System Design ◽  
Load Capacity ◽  
Engine Performance ◽  
Maximum Load ◽  
Transmission System ◽  
Published Data ◽  
Planetary Gearbox ◽  
Open Rotor ◽  
Parametric Analyses ◽  
The Impact

Abstract This study introduces an innovative approach to sizing a differential planetary gearbox for a counter-rotating open rotor application. An updated methodology is proposed for the design of maximum load capacity gears based on the power transmitted, durability and space-envelope requirements of the application. The reported methodology has been validated by comparing the results to published data, demonstrating a maximum difference of 0.6% in geometry. Parametric analyses have also been performed to assess the impact of the design assumptions on gearbox dimensional trends. The proposed methodology enables the assessment of the impact of the preliminary transmission system design on engine performance and general arrangement. The characteristics of the gearset lead to an unequal torque split between output shafts (i.e. the propeller shafts). Given the design assumptions made, the study indicates that valid torque ratios would lie between 1.1 and 1.33. The impact of the torque ratio on the size of the gearbox has been analysed for equal rotational speeds and for different speeds between the output shafts. The study established that the transmission system design needs to be considered prior to selection of the torque ratio at engine design level.

Chemical Kinetic Study on Reaction Pathway of Anisole Oxidation at Various Operating Condition

2020 ◽  
Author(s):  
Shrabanti Roy ◽  
Omid Askari
Keyword(s):  
Kinetic Study ◽  
Equivalence Ratio ◽  
Initial Conditions ◽  
Reaction Pathway ◽  
Chemical Kinetic ◽  
Chemical Mechanism ◽  
Experimental Result ◽  
Alternative Source ◽  
Stirred Reactor ◽  
Constant Volume Combustion Chamber

Abstract Biofuels are considered as an alternative source of energy which can decrease the growing consumption of fossil fuel, hence decreasing pollution. Anisole (methoxybenzene) is a potential source of biofuel produced from cellulose base compounds. It is mostly available as a surrogate of phenolic rich compound. Because of the attractive properties of this fuel in combustion, it is important to do detail kinetic study on oxidation of anisole. In this study a detail chemical mechanism is developed to capture the chemical kinetics of anisole oxidation. The mechanism is developed using an automatic reaction mechanism generator (RMG). To generate the mechanism, RMG uses some known set of species and initial conditions such as temperature, pressure, and mole fractions. Proper thermodynamic and reaction library is used to capture the aromaticity of anisole. The generated mechanism has 340 species and 2532 reactions. Laminar burning speed (LBS) calculated through constant volume combustion chamber (CVCC) at temperature ranges from 460–550 K, pressure of 2–3 atm and equivalence ratio of 0.8–1.4 is used to validate the generated mechanism. Some deviation with experimental result is observed with the newly generated mechanism. Important reaction responsible for LBS calculation, is selected through sensitivity analysis. Rate coefficient of sensitive reactions are collected from literature to modify and improve the mechanism with experimental result. The generated mechanism is further validated with available ignition delay time (IDT) results ranging from 10–20 atm pressure, 0.5–1 equivalence ratio and 870–1600 K temperature. A good agreement of results is observed at different operating ranges. Oxidation of anisole at stoichiometric condition and atmospheric pressure in jet stirred reactor is also used to compare the species concentration of the mechanism. This newly generated mechanism is considered as a good addition for further study of anisole kinetics.

A Simplified Method to Evaluate the Impact of Component Design on Engine Performance

2007 ◽  
Author(s):  
Francesco Montella ◽  
J. P. van Buijtenen
Keyword(s):  
Design Process ◽  
Engine Performance ◽  
Simulation Software ◽  
Fast Method ◽  
Engine Simulation ◽  
Engine Model ◽  
Component Design ◽  
Wide Range ◽  
Engine Component ◽  
The Impact

This paper presents a simplified and fast method to evaluate the impact of a single engine component design on the overall performance. It consists of three steps. In the first step, an engine system model is developed using available data on existing engines. Alongside the cycle reference point, a sweep of operating points within the flight envelop is simulated. The engine model is tuned to match a wide range of conditions. In the second step, the module that contains the engine component of interest is analyzed. Different correlations between the component design and the module efficiency are investigated. In the third step, the deviations in efficiency related to different component configurations are implemented in the engine baseline model. Eventually, the effects on the performances are evaluated. The procedure is demonstrated for the case of a two-spool turbofan. The effects of tip leakage in the low pressure turbine on the overall engine performance are analyzed. In today’s collaborative engine development programs, the OEMs facilitate the design process by using advanced simulation software, in-house available technical correlations and experience. Suppliers of parts have a limited influence on the design of the components they are responsible for. This can be rectified by the proposed methodology and give subcontractors a deeper insight into the design process. It is based on commercially available PC engine simulation tools and provides a general understanding of the relations between component design and engine performance. These relations may also take into account of aspects like production technology and materials in component optimization.

Influence of a Thermal Barrier Coating on the Performance of a Turboprop Engine

1992 ◽  
Author(s):  
J. D. MacLeod ◽  
J. C. G. Laflamme
Keyword(s):  
Surface Roughness ◽  
Thermal Barrier Coating ◽  
Coating Thickness ◽  
Ceramic Coating ◽  
National Research Council ◽  
Engine Performance ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Project Objectives ◽  
The Impact

Under the sponsorship of the Canadian Department of National Defence, the Engine Laboratory of the National Research Council of Canada has evaluated the influence of applying a thermal barrier coating on the performance of a gas turbine engine. The effort is aimed at quantifying the performance effects of a particular ceramic coating on the first stage turbine vanes. The long term objective of the program is to both assess the relative change in engine performance and compare against the claimed benefits of higher possible turbine inlet temperatures, longer time in service and increased time between overhauls. The engine used for this evaluation was the Allison T56 turboprop with the first stage turbine nozzles coated with the Chromalloy RT-33 ceramic coating. The issues addressed in testing this particular type of hot section coating were; 1) effect of coating thickness on nozzle effective flow area; 2) surface roughness influence on turbine efficiency; This paper describes the project objectives, the experimental installation, and the results of the performance evaluations. Discussed are performance variations due to coating thickness and surface roughness on engine performance characteristics. As the performance changes were small, a rigorous measurement uncertainty analysis is included. The coating application process, and the affected overhaul procedures are examined. The results of the pre- and post-coating turbine testing are presented, with a discussion of the impact on engine performance.

Sign in / Sign up

Export Citation Format

Share Document