Dynamometer tests, chassis

Wang, W. G., N. N. Clark, D. W. Lyons, R. M. Yang, M. Gautani, R. M. Bata, and J. L. Loth, Emissions Comparisons from Alternative Fuel Buses and Diesel Buses with a Chassis Dynamometer Testing Facility, Environ. Sci. Technol, 31, 3132-3137 (1997). 

Pelkmans L, Debal P (2006) Comparison of on-road emissions with emissions measured on chassis dynamometer test cycles. Transp Res Part D Transp Environ 11 233-241... 

Peterson, C. L., Taberski, J. S., Thompson, J. C., and Chase, L. 2000. The Effect of Biodiesel Feedstock on Regulated Emissions in Chassis Dynamometer Tests of a Pickup Truck. Trans. ASAE, 43,1371-1381. 

Phase I—Chassis Dynamometer Tests. A 1.3-L engine equipped with a four-speed automatic transmission and complete drive system was calibrated to meet 1974 emissions standards using Indolene reference fuel. This standardized apparatus was then used in conjunction with the federal emissions test procedure to evaluate the performance of methanol/gasoline blends. Results of the single cylinder test program and preliminary evaluations with the chassis dynamometer system indicated that blends should be limited to 10% methanol or less to avoid drive-ability and other problems. A complete discussion of the apparatus and test procedures is given in Ref. 9. 

The results of the chassis dynamometer test program are presented in Figures 12 and 13. For the base fuels tested, the most notable change is the decrease in CO emissions. A nominal reduction of 30% is obtained by adding 10% methanol to the base unleaded gasoline. This reduction has also been noted by Wigg and Lunt (11) and by Brinkman et al. (12). 

Figure 16, Chassis dynamometer test results Indo-lene-30 base fuel...

The back pressure was measured for two different preconverter assemblies (all catalyzed) in a chassis dynamometer test [4-liter, 6-cylinder engine with port fuel injection (PFI)]. Both preconverters had identical outside dimensions and catalyst loading but different cell structures. The back pressure, measured with the aid of H2O monometers, is summarized in Table 20. The differences in back pressure across the two preconverters are attributed to both the back pressure parameter and the frictional drag of catalyzed... 

Table 20 Back Pressure Data for Two Different Preconverters During Chassis Dynamometer Test 50 miles/hr ...

Perform chassis dynamometer tests under steady-state conditions, and road tests to evaluate fuel consumption and drivability. 

Table 6 Back Pressure Data for Three Different Preconverters during Chassis Dynamometer Test 80 km/hr (93 mm diameter x 90 mm long preconverter with inlet gas temp. = 700°C) ...

The back pressure measurements in the chassis dynamometer test have also shown that the EX-22 ceramic preconverter is a viable candidate for light-off application. 

K.J. Kelly, M. Mihalic, M. Zolot (National Renewable Energy Laboratory), Battery usage and thermal performance of the Toyota Prius and Honda Insight during chassis dynamometer testing . The Seventeenth Annual Battery Conference on Applications and Advances, Long Beach, Cahfomia, 14-18 January 2002. 

The test for evaluating individual vehicle emissions, the ETP (4), specifies that a test vehicle be stored in an area where the ambient temperature is between 20 and 29°C for at least 12 hours immediately prior to the emission test. Then, the vehicle is placed on a chassis dynamometer which is calibrated for the vehicle weight and road load. The vehicle is started and driven for 41 min on a prescribed cycle of accelerations, cmises, decelerations, idles, a 10-min shutdown (called the hot soak), and a period of remn. 

The EPA regulation prohibits more than 2 grams per test to escape into the atmosphere (114). The test consists of a diurnal cycle of 1 hour where the temperature of the fuel is raised from 15.6 to 28.9°C during a 17 mile mn on a chassis dynamometer. An immediate hot soak in a shed enclosure follows the dynamometer mn. 

Road Octane—A numerical value based upon the relative antiknock performance of an automobile with a test gasoline as compared with specified reference fuels. Road octanes are determined by operating a car over a stretch of level road or on a chassis dynamometer under conditions simulating those encountered on the highway. 

Tables 1 and 2 sununarize the development of the legislation in the United States from the time when serious attention was paid to reducing emissions from automobiles. From 1977 in California, where there were some particularly pressing air-quality problems [3], they were allowed to legislate lower levels of emissions than in the rest of the United States. The emission numbers are generated by driving the vehicle on a chassis dynamometer (rolling road) to a well-defined test drive cycle (see Fig. 1). This cycle represents conditions typical on a U.S. freeway and has a maximum speed of 55 mph. The emissions are collected from the tailpipe as soon as the ignition is switched on, analyzed, and the pollutant concentrations calculated. It can be seen from the table that emission limits are decreasing steadily, especially from 1993 onward, and that over the period there has been a major reduction in the emission levels. With the introduction of each successive emissions band, a small percentage of vehicles are required to meet the next band. This culminates in a requirement for a small number of vehicles to emit zero emissions in the year 2000, which can be achieved currently only by electric vehicles.

The exhaust gas emissions from passenger cars and light duty vehicles are generally measured in a vehicle test, in which a vehicle is mounted on a chassis dynamometer... 

Several vehicle driveability tests using trained drivers were conducted with MTG gasoline (ref. 17). These tests included studies with New Zealand-type cars, six 1981-model US cars, and 34 cars. The latter test was a consumer-type test and included 23 US, 6 Japanese, and 5 European cars. The tests were conducted under a wide range of ambient conditions. For example, with the New Zealand-type cars, the tests were conducted in all-weather chassis dynamometer rooms at temperatures ranging from -18 to 32 C... 

The results presented in this section were obtained with a carbureted vehicle that was mounted on a chassis dynamometer and that was driven through the U.S. FTP. All of the data presented are for operation following warm-up of the catalyst (i.e., accel-decel cycles number four and greater). Two complete sets of emission analyzers allowed simultaneous measurement of exhaust composition at the inlet and outlet of the pellet-type catalytic converter. Here we present a brief review of the results of these tests. A more detailed description is given in (ref.4). 

The formulation of emission factors for mobile sources, the major sources of VOCs and NO, is based on rather complex emission estimation models used in conjunction with data from laboratory testing of representative groups of motor vehicles. Vehicle testing is performed with a chassis dynamometer, which determines the exhaust emission of a vehicle as a function of a specified ambient temperature and humidity, speed, and load cycle. The current specified testing cycle is called the Federal Test Procedure (FTP). On the basis of results from this set of vehicle emissions data, a... 

Final test results were performed on a chassis dynamometer according to the European MVEG-A test procedure. The passenger car used had a inertia weight of 1500 kg and was equipped with a 2.5 1 DI/TC four cylinder diesel engine. 

All exhaust emission tests were carried out on a chassis dynamometer using different driving cycles. 

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