In the case of LPG, sequential vapor phase injection systems are the largest group, mainly due to their versatility. The use of low-carbon fuels is currently dominated by liquefied petroleum gas (LPG) and compressed natural gas (CNG). Despite the steadily increasing number of hybrid, electric or H 2-powered vehicles, internal combustion engines still represent a large part of the car market, especially in the group of vehicles already in operation. Various measures are used in transport vehicles to meet this expectation, such as vehicle weight reduction combined with engine displacement reduction and turbocharging or the use of low-carbon fuels. Reducing CO 2 emissions falls under the general scope of greenhouse gases (GHGs). In the automotive industry, great emphasis is placed on reducing CO 2 emissions. Piezoelectric transducers are used, for example, in medicine, agriculture and the automotive industry. The principle of their operation is based on the conversion of electrical energy into mechanical energy or vice versa. SMs include piezoelectric materials which, in combination with other materials, are commonly used as converters enabling the measurement and/or regulation of various physical quantities such as force, deformation, temperature and pressure. The stimulus causing the change can be a magnetic/electric field, stress or temperature. SMs are defined as materials whose behavior changes in a systematic way. Recently, due to the functional features, strong development and application of intelligent smart materials (SMs) have been noticeable. Moreover, it was found that among the tested material combinations, the transducer made of silicon oxide and PTZ5H (soft piezoelectric ceramics) had the lowest energy consumption. On the basis of the performed tests, it was found that the energy demand is most influenced by the relative stiffness of the transducer materials (Young’s modulus ratio) and the piezoelectric constant of the active component ( d 31). As for the active components of the converter, it was assumed that they could be made of polymeric or ceramic piezoelectric materials. In the performed analyses, it was assumed that the passive elements of the actuator are made of typical materials used in micro-electromechanical systems (MEMSs) (copper, nickel, silicon alloys and aluminum alloys). Assuming a constant transducer geometry, 40 variants of material combinations were considered. On this basis, the energy demand of the converter, required to obtain the desired valve opening, was determined. Thus, its static electromechanical characteristics were found in analytical form. The opening and closing of the injector valve are controlled by a piezoelectric transducer. Therefore, a spatial model of the complete injector was developed, and the necessary flow analyses were performed using computational fluid dynamics (CFD) in Ansys Fluent environment. To ensure the functionality of the injector, its flow characteristics and the effective range of valve opening had to be determined. The transducer is intended for use in a low-pressure gas-phase injector executive system. This paper presents the results of research related to the selection of materials for passive and active components of a three-layer piezoelectric cantilever converter.
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