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This paper is a continuation of work previously discussed in SAE 2014-01-0179 [1] and SAE 2015-01-0805 [2], which was intended to improve the capability and precision of the Ignition Quality Tester (IQT™) and associated ASTM D6890 [3]/CEN EN 15195 [4]/EI IP 498 [5] Test Methods. The results presented in those two papers indicated how the new generation of IQT™ with the TALM Precision Package upgrade can markedly improve the precision of the ASTM D6890, CEN EN 15195 and EI IP 498 Derived Cetane Number (DCN) test methods. This paper will evaluate the performance of the upgraded instruments over the past 21 months of their participation in ASTM’s National Fuel Exchange Group (NEG) diesel fuel exchange program.

This paper presents the results of a mini Inter-Laboratory Study (mILS) that is a continuation of earlier work, published in SAE paper number 2014-01-0179 [1]. This work was aimed to improve the capability, precision, and durability of the Ignition Quality Tester (IQT™) and ASTM D6890 [2]/EN15195 [3] Test Methods. The mILS was performed to determine how much the TALM IQT™ Precision Package would improve the precision of four IQT™s, relative to a larger number of IQT™s participating in two separate Fuel Exchange Programs (FEPs). Two of the IQT™s were located at AET and the other two were located at two different external laboratories. All four IQT™s were equipped with the TALM Precision Package. Nine fuel samples from the two FEPs with reference DCN values from 33 to 82 were selected for testing.

This paper draws from several recent activities conducted at Advanced Engine Technology Ltd. (AET) which were aimed at improving the capability, precision, and durability of the Ignition Quality Tester (IQT™). The paper includes descriptions of the current Totally Automated Lab Model IQT™-TALM technology, recent experimental results such as updates to the IQT™ measurement capabilities and a summary of a Micro Intra-Laboratory Study (μILS) results. The results show that the standard deviation of Derived Cetane Number for most of the fuel samples tested was considerably lower than that obtained when those fuel samples were tested in the ASTM National Exchange Group and Energy Institute diesel fuel exchange programs.

In this study, the injection spray of the IQT™ is characterized under atmospheric back pressure using phase doppler anemometry (PDA). Viscor calibration fluid, which has diesel-like fluid properties, is injected using the complete injection system of the IQT™. The high temporal resolution of the PDA method allowed precise time-resolved analysis of droplet size and velocity. The AMD and SMD of fuel droplets are found to be 9.3 and 29.3 μm, respectively. The velocity is analyzed as a function of radial position from the nozzle axis. The droplet velocity varies between 130 m/s and 10 m/s depending on spatial position and time after the start of injection. Average velocities on the axis were found to be approximately 78 m/s, decreasing to 15 m/s moving towards the outer spray periphery. The droplet count as a function of radial position suggests that most droplets form a cone angle of 12.6°, which is in agreement with a series of high speed images captured using front light photography.

The spatial distribution of drops in sprays is critical to the performance of many atomization systems, including diesel engine injectors, gas turbine injectors, spray coating systems, and furnace burners. This paper presents an investigation of the effects of nozzle fuel spray pattern on the measurement of cetane number as determined in the Ignition Quality Tester (IQT™). To determine the effects of spray pattern on cetane number, an optical spray pattern test rig was developed. The test rig was comprised of the IQT™ fuel injection system and data acquisition system, and the Optical Spray Pattern Analyzer from Nexum. Several nozzles from different manufacturers where chosen for this study. Cetane numbers for a diesel reference fuel were obtained for each of the test nozzles in the IQT™ and where compared qualitatively to spray pattern images for each of the test nozzles observed from the spray pattern test rig.

A study was conducted to investigate the effects of diesel fuel lubricity on diesel engine fuel injection equipment (FIE) wear and failure rates, for diesel fuels with poor to moderate lubricity characteristics, with and without lubricity additives. Five tests were used to evaluate diesel fuel lubricity characteristics: 1) a modified Falex Corporation Ball-on-Three-Disk (BOTD) lubricity test rig; 2) a high-speed Detroit Diesel Corporation (DDC) 8V71T engine test rig operated at maximum load and speed conditions under elevated fuel, coolant and ambient temperatures; 3) a Wärtsilä VASA 9R32, medium-speed, diesel engine electric power generation unit in Iqaluit, Nunavut, Canada, 4) a fuel pump rig (FPR) and 5) a high frequency reciprocating rig (HFRR).

This paper reports on the fourth part of a continued study on further research and development with the automated Ignition Quality Tester (IQT™). Research over the past six years (reported in SAE papers #961182, 971636 and 1999-01-3591) has demonstrated the capabilities of this automated apparatus to measure the ignition quality and accurately determine a derived cetane number (DCN) for a wide range of middle distillate and non-conventional diesel fuels. The present paper reports on a number of separate investigations supporting these continued studies.

This paper reports on the third part of a continued study (SAE Papers 961182, 971636) to develop the Ignition Quality Tester (IQT™). Past research has shown that this automated laboratory/refinery apparatus can be used to accurately predict the cetane number of middle distillates and alternative fuels using small sample volumes (< 50 mL). The paper reports on the main objective of a study performed by Advanced Engine Technology Ltd. (AET), in co-operation with its research partners. The primary research objective of this work is to further the understanding of fuel preparation (fuel air mixing) and start of combustion processes in the IQT™. Key to this understanding is the manner in which single molecule compounds and full boiling-range diesel fuels behave during these processes. Insights are provided into the manner in which the American Society for Testing and Materials (ASTM) D-613 primary reference fuels (PRFs) undergo fuel preparation and start of combustion in the IQT™.