In-Use Heavy-Duty Diesel Emissions Measurement Using an Air-to-Fuel Ratio Derived Exhaust Flow Rate

Author(s):  
John Nuszkowski ◽  
Jason D. Bolyard ◽  
Gregory J. Thompson ◽  
Daniel K. Carder

Emissions produced by internal combustion engines during laboratory testing have been shown to not fully represent real world applications. Raw emissions measurements have aided the study of vehicle emissions resulting from in-use applications. In-use emissions measurements may be cumbersome; being that direct measurement of exhaust flow rate will often require that the vehicle exhaust system be modified. This paper investigated the feasibility of substituting exhaust air-to-fuel ratio and ECU fuel flow rates for the inferred measurement of exhaust flow rates. The air-to-fuel ratio for a diesel application was solved from the measured raw emissions of CO2, O2, and NOx. A 2002 Ford F-650, powered by a 2002 Cummins ISB diesel engine, was fitted with an Annubar™ exhaust flow rate measurement system (averaging pitot tube) in order to directly measure continuous exhaust flow rates. Concurrently, exhaust flow rates were estimated from air-to-fuel ratio, while “theoretical” exhaust flow rates were derived from engine speed, intake air density, and assumed volumetric efficiency. These surrogate measurements of exhaust flow rates were then compared with the direct measurements of flow rates obtained by the Annubar™ system. Fuel consumption estimates based on the air-to-fuel ratio derived exhaust flow rate and CO2, theoretical exhaust flow rate and CO2, and measured exhaust flow rates and CO2 were then compared with reported ECU fueling rates over the entire test and during NTE events. An error analysis was performed on the air-to-fuel ratio exhaust flow rate equation to quantify uncertainty resulting from the measurements and assumed parameters. The results showed that the air-to-fuel ratio derived exhaust flow rates compared well with the measured exhaust flow rates and the theoretical exhaust flow rates with an R2 value of 0.982 and 0.986, respectively. During highly transient events and motoring conditions, the air-to-fuel ratio derived exhaust flow rates were inaccurate due to analyzer response and zero fueling conditions, respectively. However, during steadier operation, the air-to-fuel ratio derived exhaust flow rate compared to the measured exhaust flow rate and the theoretical exhaust flow rate within 3.5% and 1.9%, respectively. Overall measurement uncertainty was most affected by the CO2 analyzer at high AFRs. The resulting fuel consumptions from AFR derived exhaust flow rate, theoretical exhaust flow rate, and MEMS exhaust flow rate compared to within 2% of each other. The ECU fuel consumption was 5–7% higher than the MEMS, AFR derived, and theoretical.

Author(s):  
Per Stralin ◽  
Achintya Mukhopadhyay ◽  
Ishwar K. Puri

Nozzle-mix burners are widely used in heat treatment and non-ferrous melting furnaces, and other applications, where temperature uniformity is required. These burners are stable over a wide range of air-fuel ratios from very lean to rich (up to 50% of excess fuel), high turndown ratio and low NOX emissions at all air-fuel ratios. Here, the fuel is generally transported by a central jet and air through an annular jet. The separation between the fuel jet and the air annulus and confining wall are crucial for flame stabilization. The objective of the present work is to investigate the flow and flame characteristics of a nonpremixed nozzle-mix burner through a detailed parametric study. The inferences from this study will provide useful information for designers, regarding choice of parameters. The burner is modeled as an axisymmetric arrangement of fuel duct at the center, surrounded by a coaxial annular duct of air. The ducts discharge into a confined environment, formed by a chimney, placed coaxially with the ducts. The results of the numerical simulation show that for a given air-fuel ratio, as the fuel flow rate increased, the location of the flame base shifted from near the fuel nozzle towards the oxidizer nozzle. Similar shift in flame position was also observed for higher air velocities for a given fuel velocity. High fuel and air flow rates and small separation between fuel and air jets tend to destabilize the flame. For a given air-fuel ratio, flame height increased with increase in fuel flow rates, but the change became insignificant at higher flow rates. For a given fuel velocity, flame height decreased with increase in air flow rate for both buoyancy-controlled and momentum-controlled regimes. The air-to-fuel velocity ratio was found to be the most significant parameter in determining the flame height.


2020 ◽  
Vol 124 (1278) ◽  
pp. 1170-1189
Author(s):  
C. Cai ◽  
L. Guo ◽  
J. Liu

ABSTRACTThe gas temperature of the supersonic heat airflow simulated test system is mainly determined by the fuel and air flow rates which enter the system combustor. In order to realise a high-quality control of gas temperature, in addition to maintaining the optimum ratio of fuel and air flow rates, the dynamic characteristics of them in the combustion process are also required to be synchronised. Aiming at the coordinated control problem of fuel and air flow rates, the mathematical models of fuel and air supply subsystems are established, and the characteristics of the systems are analysed. According to the characteristics of the systems and the requirements of coordinated control, a fuzzy-PI cross-coupling coordinated control strategy based on neural sliding mode predictive control is proposed. On this basis, the proposed control algorithm is simulated and experimentally studied. The results show that the proposed control algorithm has good control performance. It cannot only realise the accurate control of fuel flow rate and air flow rate, but also realise the coordinated control of the two.


Author(s):  
Andrew G. Smith ◽  
Suresh Menon ◽  
Jeffery A. Lovett ◽  
Baris A. Sen

Large eddy simulations (LES) are performed of a bluff-body–stabilized flame with discrete liquid fuel injectors located just upstream of the bluff-body trailing edge in a so-called “close-coupled” configuration. Nonreacting and reacting simulations of the Georgia Tech single flameholder test rig [Cross et al., 2010, “Dynamics of Non-premixed Bluff Body-Stabilized Flames in Heated Air Flow,” Proceedings of ASME Turbo Expo, Paper No. GT2010-23059] are conducted using an Eulerian–Lagrangian approach with a finite volume solver. Experimental data is first used to characterize the boundary conditions under nonreacting conditions before simulating reacting test cases at two different fuel mass flow rates. The two fuel mass flow rates not only result in different global equivalence ratios but different spatial distributions of fuel, especially in the near-field wake of the bluff body. The differing spatial distribution of fuel results in two distinct flame dynamics; at the high-fuel flow rate, large-scale sinusoidal Bérnard/von-Kármán (BVK) oscillations are observed, whereas a symmetric flame is seen under the low-fuel flow rate condition.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ridvan Oruc ◽  
Tolga Baklacioglu

Purpose The purpose of this paper is to create a new fuel flow rate model for the descent phase of the flight using particle swarm optimization (PSO). Design/methodology/approach A new fuel flow rate model was developed for the descent phase of the B737-800 aircraft, which is frequently used in commercial air transport using PSO method. For the analysis, the actual flight data records (FDRs) data containing the fuel flow rate, speed, altitude, engine speed, time and many more data were used. In this regard, an empirical formula has been created that gives real fuel flow rate values as a function of altitude and true airspeed. In addition, in the fuel flow rate predictions made for the descent phase of the specified aircraft, a different model has been created that can be used without any optimization process when FDR data are not available for a specific aircraft take-off weight condition. Findings The error analysis applied to the models showed that both models predict real fuel flow rate values with high precision. Practical implications Because of the high accuracy of the PSO model, it is thought to be useful in air traffic management, decision support systems, models used for trajectory prediction, aircraft performance models, strategies used to reduce fuel consumption and emissions because of fuel consumption. Originality/value This study is the first fuel flow rate model for descent flight using PSO algorithm. The use of real FDR data in the analysis shows the originality of this study.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3649
Author(s):  
Francisco Velásquez-SanMartín ◽  
Xabier Insausti ◽  
Marta Zárraga-Rodríguez ◽  
Jesús Gutiérrez-Gutiérrez

In this paper we propose a mathematical model for the fuel consumption analysis during aircraft cruise. A closed-form formula that expresses the aircraft’s weight variation over time, and hence, the fuel flow rate, is obtained as a result. Furthermore, a closed-form expression of the aircraft’s main performance parameters is also obtained. We compare the values of such parameters computed by using the Piano-X software and computed by using our mathematical model. Simulation results confirm that our mathematical model provides results very close to reality. Finally, the closed-form formula of the fuel flow rate provided by our model is used to improve the calculation of the carbon dioxide emissions for four example routes, which, unlike here, are usually obtained under the assumption of a constant value of the fuel flow rate.


2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ridvan Oruc ◽  
Ozlem Sahin ◽  
Tolga Baklacioglu

Purpose The purpose of this paper is to create a new fuel flow rate model using cuckoo search algorithm (CSA) for the descending stage of the flight. Design/methodology/approach Using the actual flight data record data of the B737-800 aircraft, a new fuel flow rate model has been developed for this aircraft type. The created model is to predict the fuel flow rate with high accuracy depending on the altitude and true airspeed. In addition, the CSA fuel flow rate model was used to calculate the fuel consumption for the point merge system, which is used for combining the initial approach to the final approach at Istanbul Airport, the largest airport of Turkey. Findings As a result of the analysis, the correlation coefficient value is found as 0.996858 for Flight 1, 0.998548 for Flight 2, 0.995363 and 0.997351 for Flight 3 and Flight 4, respectively. The values that are so close to 1 indicate that the model predicts the real fuel flow rate data with high accuracy. Practical implications This model is considered to be useful in air traffic management decision support systems, aircraft performance models, models used for trajectory prediction and strategies used by the aviation community to reduce fuel consumption and related emissions. Originality/value The importance of this study lies in the fact that to the best of the authors’ knowledge, it is the first fuel flow rate model developed using CSA for the descent stage in the existing literature; the data set used is real values.


Author(s):  
Tongxun Yi ◽  
Domenic A. Santavicca

Reported is a practical method for accurate and fast determination of the instantaneous fuel flow rate out of a fuel injector. Both gaseous and liquid fuels are considered. Unsteady fuel flow rates introduced into a combustor can be caused by both self-excited pressure pulsations and fuel modulations. During combustion instability, the air flow rate into a combustor also varies in response to pressure pulsations. Accurate determination of the instantaneous fuel and air flow rates is important for both modeling and control of combustion instability. The developed method is based on the acoustic wave theory and pressure measurements at two locations upstream of a fuel injector. This method bypasses the complexities and nonlinearities of fuel actuators and fuel nozzles, and works for systems with slow-time-varying characteristics. Acoustic impedance of a gaseous fuel nozzle is found to be a function of multivariables, including the forcing frequency, the acoustic oscillation intensity, and the mean fuel flow rate. Thus, it is not an intrinsic property of the fuel injector alone. In the present study, sharp tubing bending with almost zero radii is found to have minimal effects on the distribution of 1D acoustic wave. This is probably because vortex shedding and recirculation at tubing corners do not alter the globally 1D characteristics of acoustic wave distribution. Different from the traditional two-microphone method, which determines the acoustic velocity at the middle locations of the two microphones, the present method allows the acoustic velocity, the acoustic mass flux, and the specific acoustic impedance to be determined along the fuel tubing or an air pipe.


Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.


1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.


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