scholarly journals Increasing accuracy and repeatability of fuel consumption measurement in chassis dynamometer testing

Author(s):  
C J Brace ◽  
R Burke ◽  
J Moffa

The aim of this paper is to identify and investigate the effect of small changes in test conditions when quantifying fuel consumption. Twelve test set-up variables were identified and intentionally perturbed from a standard condition, including the effect of removing the power-assisted steering pump. Initially a design-of-experiments (DoE) approach was adopted and the results showed that most of the tested parameters had significant effects on fuel consumption. Most of these effects were greater than the effect of typical technology changes assessed on chassis dynamometer facilities. For example, an increase of 8.7 per cent in fuel consumption was observed following a 90min battery discharge from vehicle headlamps. Similarly an increase of 5.5 per cent was observed when the rig was run 3km/h faster over a drive cycle, and 2.6 per cent when using tyres deflated by 0.5 bar. As a consequence, statistical tolerancing was used to suggest typical tolerances for test rig set-up variables. For example it was recommended that the tyre pressure be controlled to within 0.1 bar and the test rig speed to 0.3km/h. Further investigations were conducted into the effect of battery discharge, coast-down time, and engine cooling. These highlighted the need for rigorous battery charge management as the battery voltage was found not to be an appropriate measure of the variation in the alternator loading. Coast-down time was found to be a good control measure for a number of set-up variables affecting the rolling resistance of the vehicle. Finally the variations in the engine cooling were quantified using a cumulative engine temperature over a drive cycle. This was found to correlate well with fuel consumption. For each of these subsequent investigations, results were compared with the DoE predictions and found to agree well when considering the relatively low number of tests compared with the number of factors.

Author(s):  
Peter Vasquez ◽  
Edwin Quiros ◽  
Gerald Jo Denoga ◽  
Robert Michael Corpus ◽  
Robert James Lomotan

Abstract Efforts to mitigate climate change include lowering of greenhouse gas emissions by reducing fuel consumption in the transport sector. Various vehicle technologies and interventions for better fuel economy eventually require chassis dynamometer testing using drive cycles for validation. As such, the methodology to generate these drive cycles from on-road data should produce drive cycles that closely represent actual on-road driving from the fuel economy standpoint. This study presents a comparison of the fuel economy measured from a drive cycle developed using road load energy as a major assessment criterion and the actual on-road fuel economy of a 2013 Isuzu Crosswind utility vehicle used in the UV Express transport fleet in Metro Manila, Philippines. In this approach to drive cycle construction from on-road data, the ratio of the total road load energy of the generated drive cycle to that of the on-road trip is made the same ratio as their respective durations. On-road velocity and fuel consumption were recorded as the test vehicle traversed the 42.5 km. Sucat to Lawton route and vice versa in Metro Manila. Gathered data were processed to generate drive cycles using the modified Markov Chain approach. Three drive cycles of decreasing duration, based on the practicality of testing on a chassis dynamometer, were generated using three arbitrary data compression ratios. These drive cycles were tested using the same vehicle on the chassis dynamometer and compared with the on-road data using road load energy, fuel economy, average speed, and maximum acceleration. For the 893-seconds drive cycle generated, the road load energy error was 3.93% and fuel economy difference of 1.14%. For the 774-seconds cycle generated, the road load energy error was 4.34% and fuel economy difference was 0.91%. For the 664-seconds drive cycle, the road load energy error was 3.68% and fuel economy difference was 0.91%. On-road fuel economy for the 42.5-km. route averaged over nine round trips was 8.785 km/L. Based on the results, the road load energy criterion approach of drive cycle construction methodology can generate drive cycles which can very closely estimate on-road fuel economy.


Author(s):  
Stefan Schmid ◽  
Rudi Kulenovic ◽  
Eckart Laurien

For the validation of empirical models to calculate leakage flow rates in through-wall cracks of piping, reliable experimental data are essential. In this context, the Leakage Flow (LF) test rig was built up at the IKE for measurements of leakage flow rates with reduced pressure (maximum 1 MPA) and temperature (maximum 170 °C) compared to real plant conditions. The design of the test rig enables experimental investigations of through-wall cracks with different geometries and orientations by means of circular blank sheets with integrated cracks which are installed in the tubular test section of the test rig. In the paper, the experimental LF set-up and used measurement techniques are explained in detail. Furthermore, first leakage flow measurement results for one through-wall crack geometry and different imposed fluid pressures at ambient temperature conditions are presented and discussed. As an additional aspect the experimental data are used for the determination of the flow resistance of the investigated leak channel. Finally, the experimental results are compared with numerical results of WinLeck calculations to prove specifically in WinLeck implemented numerical models.


Author(s):  
Kevin Laboe ◽  
Marcello Canova

Up to 65% of the energy produced in an internal combustion engine is dissipated to the engine cooling circuit and exhaust gases [1]. Therefore, recovering a portion of this heat energy is a highly effective solution to improve engine and drivetrain efficiency and to reduce CO2 emissions, with existing vehicle and powertrain technologies [2,3]. This paper details a practical approach to the utilization of powertrain waste heat for light vehicle engines to reduce fuel consumption. The “Systems Approach” as described in this paper recovers useful energy from what would otherwise be heat energy wasted into the environment, and effectively distributes this energy to the transmission and engine oils thus reducing the oil viscosities. The focus is on how to effectively distribute the available powertrain heat energy to optimize drivetrain efficiency for light duty vehicles, minimizing fuel consumption during various drive cycles. To accomplish this, it is necessary to identify the available powertrain heat energy during any drive cycle and cold start conditions, and to distribute this energy in such a way to maximize the overall efficiency of the drivetrain.


2018 ◽  
Author(s):  
Adriaan Smuts Van Niekerk ◽  
Benjamin Drew ◽  
Neil Larsen ◽  
Peter Kay

To reduce the amount of carbon dioxide released from transportation the EU has implemented legislation to mandate the renewable content of petrol and diesel fuels. However, due to the complexity of the combustion process the addition of renewable content, such as biodiesel and ethanol, can have a detrimental effect on other engine emissions. In particular the engine load can have a significant impact on the emissions. Most research that have studied this issue are based on steady state tests, that are unrealistic of real world driving and will not capture the difference between full and part loads. This study aims to address this by investigating the effect of renewable fuel blends of diesel, biodiesel and ethanol on the emissions of a compression ignition engine tested over the World Harmonised Light Vehicle Test Procedure (WLTP). Diesel, biodiesel and ethanol were blended to form binary and ternary blends, the ratios were determined by Design of Experiments (DoE). The total amount of emissions for CO, CO2 and NOx as well as the fuel consumption, were measured from a 2.4 liter compression ignition (CI) engine running over the WLTP drive cycle. The results depicted that percentages smaller than 10 % of ethanol in the fuel blend can reduce CO emissions, CO2 emissions as well as NOx emissions, but increases fuel consumption with increasing percentage of ethanol in the fuel blend. Blends with biodiesel resulted in minor increases in CO emissions due to the engine being operated in the low and medium load regions over the WLTP. CO2 emissions as well as NOx emissions increased as a result of the high oxygen content in biodiesel which promoted better combustion. Fuel consumption increased for blends with biodiesel as a result from biodiesel's lower heating value. All the statistical models describing the engine responses were significant and this demonstrated that a mixture DoE is suitable to quantify the effect of fuel blends on an engine's emissions response. An optimised ternary blend of B2E9 was found to be suitable as a 'drop in' fuel that will reduce harmful emissions of CO emissions by approximately 34 %, NOx emissions by 10 % and CO2 emissions by 21 % for transient engine operating scenarios such as the WLTP drive cycle.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
C. Delprete ◽  
E. Brusa ◽  
C. Rosso ◽  
F. Bruzzone

Bearing is a crucial component of industrial equipment, since any fault occurring in this system usually affects the functionality of the whole machine. To manage this problem, some currently available technologies enable the remote prognosis and diagnosis of bearings, before that faults compromise the system function and safety, respectively. A system for the in-service monitoring of bearing, to detect any inner fault or damage of components and material, allows preventing undesired machine stops. Moreover, it even helps in performing an out-monitoring action, aimed at revealing any anomalous behaviour of the system hosting bearings, through their dynamic response. The in-monitoring can be based on the vibration signal measurement and exploited to detect the presence of defects in material. In this paper, the orthogonal empirical mode decomposition is analysed and tested to investigate how it could be effectively exploited in a lean in-service monitoring operation and remote diagnosis. The proposed approach is validated on a test rig, where an elementary power transmission line was set up. The activity highlights some main properties and practical issues of the technological implementation, as well as the precision of the Orthogonal Empirical Mode Decomposition, as a compact approach for an effective detection of bearing faults in operation.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Jie Hong ◽  
Tianrang Li ◽  
Zhichao Liang ◽  
Dayi Zhang ◽  
Yanhong Ma

Aeroengines pursue high performance, and compressing blade-casing clearance has become one of the main ways to improve turbomachinery efficiency. Rub-impact faults occur frequently with clearance decreasing. A high-speed rotor-support-casing test rig was set up, and the mechanism tests of light and heavy rub-impact were carried out. A finite element model of the test rig was established, and the calculation results were in good agreement with the experimental results under both kinds of rub-impact conditions. Based on the actual blade-casing structure model, the effects of the major physical parameters including imbalance and material characteristics were investigated. During the rub-impact, the highest stress occurs at the blade tip first and then it is transmitted to the blade root. Deformation on the impact blade tip generates easily with decreased yield strength, and stress concentration at the blade tip occurs obviously with weaker stiffness. The agreement of the computation results with the experimental data indicates the method could be used to estimate rub-impact characteristics and is effective in design and analyses process.


2019 ◽  
Vol 113 ◽  
pp. 02012
Author(s):  
Martina Hohloch ◽  
Melanie Herbst ◽  
Anna Marcellan ◽  
Timo Lingstädt ◽  
Thomas Krummrein ◽  
...  

A hybrid power plant consisting of a micro gas turbine (MGT) and a solid oxide fuel cell (SOFC) is a promising technology to reach the demands for future power plants. DLR aims to set up a MGT/SOFC hybrid power plant demonstrator based on a 3 kWel MTT EnerTwin micro gas turbine and an SOFC module with an electrical power output of 30 kWel from Sunfire. For the detailed investigation of the subsystems under hybrid conditions two separate test rigs are set up, one in which the MGT is connected to an emulator of the SOFC and vice versa. The paper introduces the set-up and the functionalities of the MGT based test rig. The special features are highlighted and the possibilities of the cyber physical system for emulation of a hybrid system are explained.


Author(s):  
Oscar F. Delgado ◽  
Nigel N. Clark ◽  
Gregory J. Thompson

Portable emissions measurement systems (PEMS) are used to perform in-use measurements for emissions inventory and regulatory applications. PEMS data represent real world conditions more accurately than chassis dynamometer or engine dynamometer testing, arguably being the most realistic method of determining exhaust emissions over a certain driving route. However, measured emissions and fuel consumption depend strongly on both the route followed and the traffic situation that the vehicle encounters. A tool for translation of emissions and fuel consumption between diverse types of vehicle activity is required. The purpose of this paper is to assess the possibility of using route-averaged properties (kinematic parameters) for translation of fuel consumption and NOx emissions for a set of eighteen heavy-duty vehicles operating over up to eight different driving routes. A linear model developed for heavy-duty vehicle chassis dynamometer data modeling has been extended to in-use heavy-duty vehicle data. Two approaches were implemented; the first approach mimicked the prior chassis dynamometer work by incorporating average vehicle speed and average positive acceleration and the second approach incorporated road grade in a characteristic power parameter. The end result is a simple method which was shown to be accurate for estimation of fuel consumption (within 5% relative error) and NOx emissions (within 12% relative error) for over-the-road vehicles over “unseen” roads or traffic situations, without the need to perform additional over-the-road tests.


Author(s):  
Toufiq El Kilali ◽  
Joe¨l Perret-Liaudet ◽  
Denis Mazuyer

This paper concerns a new experimental set-up based on an optical EHL machine fitted with a dynamic excitation system. The test rig has been built and presented in this paper. Apparatus design derives from two previously defined experimental test rig. With this new machine, we can study the dynamic behaviour of lubricated contacts under sliding conditions on the both tribological and dynamical point of view. It allows to measure the oil film thickness and to visualise the lubricated dynamically loaded contact under sliding condition. It allows also to measure the dynamic response (acceleration) of the loaded contact under harmonic or random external normal load excitation superimposed on a static one. Capabilities of the apparatus are given in this paper. In particular, theoretical and experimental results concerning the system natural frequencies.


2012 ◽  
Vol 512-515 ◽  
pp. 1459-1463 ◽  
Author(s):  
Yi Ding ◽  
De Cai Li ◽  
Qing Lei Wang ◽  
Hai Na Zhang ◽  
Zhi Li Zhang

Two different structure of dampers based on the principle of second-order buoyancy were designed in this paper. In order to verify the reduction of the vibration, a test rig was set up. On the test rig, the reduction effect of two different dampers was studied by adjusting the amount of the magnetic fluid. The experiment results indicate the relationship between the damping effect of magnetic fluid damper and the amount of magnetic fluid and this analysis result is benefit to the design of the dampers.


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