Warm-up time and number of tests for performance evaluation of a Diesel cycle engine

ABSTRACT: This research determined the engine warm-up time and the number of tests that must be carried out to obtain the performance parameters of a Diesel cycle engine. To this end, an agricultural tractor coupled to an eddy current dynamometer via a power take-off was used. Pure biodiesel (B100) was used as the fuel, and the hourly consumption was determined by means of a flowmeter. Data regarding torque, power, and hourly and specific fuel consumption was collected and analyzed at three engine warm-up times (20, 60, and 100 min). To determine the number of tests, 18 dynamometric tests were carried out to verify which of those presented the smallest experimental error, through the smallest coefficient of variation. No difference was observed in relation to the warm-up time for the analyzed variables, with a time of 20 min being enough to start the engine performance evaluations. In total, four trials were sufficient to assess engine performance and reduce experimental error.