Fast development of technology over the last decades has contributed to the adverse effects that may affect human health (both physical and mental). Such negative effects may include noise and vibration. These phenomena are accompanied by most of the technological processes. Need for more efficient and productive processes is causing rising trend in intensifying of these phenomena. It is unavoidable to increase efficiency without increasing the operating speed of machinery and equipment. The main goal of this paper is to carry out NVH (noise, vibration and harshness) analysis of engines; compression-ignition engine (diesel) and spark-ignition engine (gasoline) equipped in the same type of vehicle. But purpose is laying on presented methodology, not results of researches (but of course it will be presented too) which often (mainly) is made for failure detections. This paper will also cover influence of the engine mounting on generated acoustic vibrations followed by comparative NVH analysis of states occurring in diesel and gasoline engine. Scope of the work: a) theoretical introduction, b) presentation of vibration measurement (using LDV: Laser Doppler Vibrometry), c) NVH analysis in two types of engines, d) comparison of results, e) conclusions.
Presently, most passive safety tests are performed with a precisely specified seat position and carefully seated ATD (anthropomorphic test device) dummies. Facing the development of autonomous vehicles, as well as the need for safety verification during crashes with various seat positions such research is even more urgently needed. Apart from the numerical environment, the existing testing equipment is not validated to perform such an investigation. For example, ATDs are not validated for nonstandard seatback positions, and the most accurate method of such research is volunteer tests. The study presented here was performed on a sled test rig utilizing a 50cc Hybrid III dummy according to a full factorial experiment. In addition, input factors were selected in order to verify a safe test condition for surrogate testing. The measured value was head acceleration, which was used for calculation of a head injury criterion. What was found was an optimal seat angle −117°—at which the head injury criteria had the lowest represented value. Moreover, preliminary body dynamics showed a danger of whiplash occurrence for occupants in a fully-reclined seat.
This article presents analysis and an attempt to forecast the actual fuel consumption of the vehicle in the urban cycle. The most important factors affecting fuel consumption were discussed, in particular the influence of the driver’s driving style. Each driver drove a designated, the same route in the urban area outside the rush hour. Based on the readings from the OBD on-board computer and the mobile application, the driver’s occurrence points on the universal engine characteristics were read. On the axes of torque and rotational speed, the most frequently occurring engine work fields for each driver were determined. The author divided the driving styles of the driver according to the most common occurrence on the universal characteristics of the engine and depending on the specific fuel consumption. The author’s method has shown that it is possible to point out drivers who will certainly exceed the average fuel consumption after driving a few kilometers of the road. This method shows the possibility of using the on-board computer and OBD readings to optimize fuel consumption and match each driving style to the appropriate external and universal characteristics of the vehicle engine to use as little fuel as possible, and thus contribute to reducing CO2 emissions to the environment and consumption of fossil fuels. This method can be successfully used on all vehicles with an internal combustion engine.
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