Search Results

New heavy-duty diesel engine emission test regulations require even tougher emission limits verified with steady-state as well as transient test procedures, which are becoming increasingly important. The target of this paper is to describe the requirements and tasks for the fuel consumption measurement system and to discuss critical parameters which are essential for the layout of the fuel measurement system. The resulting fuel measurement system will be described and the performance ability will be demonstrated by measurement results and application examples. High absolute measurement accuracy of the fuel mass flow sensor, high fuel temperature control accuracy, appropriate fuel pressure control and fast time response of the complete fuel measurement system are all crucial factors needed to achieve repeatable specific fuel consumption values within 1 g/kWh and an overall time response of less than 300 ms.

The development process of a combustion engine is now a days strongly influenced by future emission regulations which require further reduction in fuel consumption and precise control of combustion process based on Intake air measurement, during engine development. Intake air flow meters clearly differentiate themselves from typical industrial gas flow meters because of their ability to measure extremely dynamic phenomenon of combustion engine. Thus, high internal data acquisition rate, short response time, ability to measure pulsating and reverse flows with lower measurement uncertainty are the factors that ensures the reliability of the results without being affected by ambient influences, sensor contamination or sensor aging. The AVL developed FLOWSONIX™ is based on ultrasonic transit time measuring principle with broad-band Capacitive Ultrasonic Transducer (CUT) characterized by an excellent air impedance matching strongly distinguishes itself by fulfilling all those requirements.