Abstract
An eddy-current brake, capable of measuring the torque and the power of internal combustion engines at desired rotational speeds, has been fully interfaced with an external NI cDAQ 9178 data logger. Thanks to this system, it is possible to collect and synchronize the data coming from the test stand and from several other sensors equipping the motors under test: a load cell used in a chrono-gravimetric fuel consumption system, many thermocouples, a lambda probe, an exhaust gas analyzer. To have a better control of the position of the throttling valve during the trials (hence a higher repeatability), a control system, based on an Arduino board, directly acts on the valve through a servomotor. Then, a series of software tools allows the interfacing of the various devices and the automatic post-processing of the acquired data (filtering of signals, recognition of data corresponding to the single engine speeds, time-averaging). The described testing equipment and the implemented procedures allow investigating, on the whole operating range of a motor (i.e., at different engine speeds and loads), each single performance parameter’s value, such as: the torque, the power, the fuel consumption of the motor, the temperature and the composition of the exhausts (up to nine different gases), the temperature of the engine head and of the cylinder block, the combustion quality and many other additional parameters describing the engine performance. This test stand, with the described post processing procedures, will be used in future works to evaluate the performance of traditional and alternative-fuelled internal combustion engines for both agricultural and co-generative applications.