Work Cycle of Internal Combustion Engine Due to Rightsizing

It is worth still working on the development of the internal combustion engine, because its time was not yet over. This was demonstrated by the author’s review of the literature, indicating at least the perspective of 2050 the universality of the engine as the primary propulsion or support in hybrid transport units. The presented considerations may have a broader perspective, when the thermodynamic problems of a thermal machine such as an internal combustion engine are indicated. This chapter deals with the issues of changing the swept volume known as downsizing/rightsizing. An equivalent swept volume was introduced, defined by the coefficients determining changes in the cylinder diameter and the stroke of the piston. An attempt was made to find the mutual relations to the efficiency of the work cycle and engine operating parameters. The research methodology was proposed as a mix of laboratory tests and theoretical analyses, on the basis of which it was established that while maintaining the same value of the downsizing index, despite the various permissible combinations of cylinder diameter and piston stroke changes, the cycle efficiency remains unchanged. The engine operating parameters are changing, resulting from the use of support systems for rightsizing geometric changes.

Dynamics of Switched Reluctance Linear Tubular Motor for Reciprocating Water Pump

Simple, cheap, and efficient water pumps are needed in developing countries. A reciprocating water pump driven by a switched reluctance linear tubular motor with double pistons that can be supplied from a photovoltaic power source seems to respond to this demand. This type of new motor (one with reciprocating motion) is presented in the paper. In order to develop a strong driving force at two extreme piston positions and achieve a long piston stroke, a double coil motor with a double secondary and two springs is proposed. Simulation results of force, current, and voltage waveforms obtained using MATLAB/Simulink are presented. The electromagnetic forces and coil inductances, which depended on the current and the secondary positions of the pistons, were determined using FEM. Simulation results are compared with those obtained from an experiment carried out on the motor prototype.

Coulisse mechanism with rotating link for operating part drive unit of the mortar pump

The synthesis of a connecting link mechanism with a rotating link with a planetary gear for driving the operating part of a piston pump during transportation of solution mixtures from the preparation site to the construction site is presented. The kinematic diagram of the axial and disaxial connecting link mechanism is given, which allow increasing the pump performance by increasing the length of the piston stroke S by 1.7 ... 3 times more than the serial pumps produced and reducing the load on the pump bearing support.

Design of 0.67hp gasoline generator pistons

Piston is an important internal combustion engine component that works with other engine components to withstand severe stresses and high temperature that are generated in the combustion chambers. Pistons are subjected to a very high mechanical and thermal load which results from extreme pressure cycles and huge forces of inertia caused by extremely high acceleration during the reciprocating motion. The 0.67hp generator piston designed had the values of parameters to be: 51.00mm Piston stroke; 48.85mm piston bore diameter; 3.66kw brake power; 4.87kw indicated power; 11.63Nm engine torque; 3.22mm piston thickness and 9.44cm3 clearance volume. The piston parameter values calculated were found to be in accordance with the recommended range of values in the design and operating data for internal combustion engines. Keywords: Piston design, machine parameters and internal combustion engines.

Kinematic and Dynamic Response of a Novel Engine Mechanism Design Driven by an Oscillation Arm

The goal of this paper is to highlight the advantage fulfilled by a novel engine mechanism, the concept of which is based on an oscillating arm relative to the classical engine mechanism. Further, the results of this paper demonstrate the benefits of a novel type of mechanism and the major advantages in terms of functioning parameters of an engine. Their performances highly depend on the joint positions of the oscillating arm. The increases in the functional performances rate of success (i.e., piston stroke, volume of the combustion chamber or compression ratio) enable a superior engine power parameter (higher power, torque) and bring some additional improvement on the eco parameters of the engine related to consumption, emission, etc.

An Innovative Miniature Pulsating Emulsification Device: Flow Characterization and Measurement of Emulsion Stability

The aim of this study is the development of an emulsification device for two immiscible liquids with a total volume of approximately 3 mL. The heart of the device is a piston, with an aluminum plate fixed at its tip, which moves periodically up and down inside a rectangular cell. The plate geometry (uniform or non-uniform height) affects significantly both the emulsions stability and the size of the droplets of the prepared emulsions. Five parameters are examined during testing (surfactant type, surfactant concentration, proportion of immiscible liquids, piston stroke frequency, duration of emulsification) and all of them appear to have an important role in the resulting droplet size distribution. A macroscopic theoretical model is developed for the determination of the main hydrodynamic parameters of the innovative device. It is shown that the non-uniform height plate achieves higher shear rates when compared to the uniform height plate because of the smaller gap between the plate and the cell walls. However, the benefits of the higher shear rate are overturned by the larger effective breakage time encountered in the uniform height plate resulting from the larger surface area of its sides. The results of the emulsification experiments are analyzed using the parameter values derived by the developed model.

PECULIARITIES OF BENCH TESTS OF HYDRAULIC DAMPER OF RAILWAY PASSENGER CAR

The studies are devoted to the scientific problem connected with the significant differences in the piston stroke values during testing of the same type of hydraulic damper by the use of different test benches and methods. The damper manufacturer uses the mechanical test bench ЛИИЖТ, the design of which was created back in Soviet times. This test bench has certain design limitations regarding the amplitude of harmonic vibrations of the drive mechanism, and therefore the dampers are tested at short piston strokes, which are 4 %; 8 %; 16 %, respectively, as a percentage of the maximum stroke of the piston. The passenger car depot, as a consumer of absorbers, conducts their tests at the more modern universal stand ИГK-90.1, which differs from the mechanical stand of the manufacturer of absorbers, both in design and in the method of testing absorbers. The purpose of the research is to confirm or deny the presence of influence of the value of the piston stroke on the expert assessment of the technical condition of the hydraulic damper. To solve this problem, the modern universal test bench ИГК-90.1 carried out experimental studies with different volumes of damping fluid in the slave cylinder of the КВЗ-ЛИИЖТ 45.30.045M type. A comparative analysis of the protocols showed that in the “compression” mode, the nature of the obtained dependences of the force and resistance parameters with an increase in the piston’s moving speed changes depending on the volume of the damping fluid in the damper’s working cylinder. The authors believe that testing the absorbers during the piston stroke of at least 80% of the maximum piston stroke allows the presence of deformations of the guide rod and the insufficient amount of damping fluid (the presence of air) in the absorber’s working cylinder. Deformation of the stem can lead to jamming in operation. The presence of air in the working cylinder of the damper is generally unacceptable since such damper is not able to absorb the vertical and horizontal vibrations of the car body in a curved section of the railway track with the height difference of the railheads 150 mm.

Experimental Testing of a Variable Displacement Pump/Motor That Uses a Hydro-Mechanically Timed Digital Valving Mechanism to Achieve Partial-Stroke Piston Pressurization (PSPP)

This work describes an efficient means to adjust the power level of an axial piston hydraulic pump/motor. Conventionally, the displacement of a piston pump is varied by changing the stroke length of each piston. Since the losses do not decrease proportionally to the displacement, the efficiency is low at low displacements. Here, with partial-stroke piston pressurization (PSPP), displacement is varied by changing the portion of the piston stroke over which the piston is subjected to high pressure. Since leakage and friction losses drop as the displacement is decreased, higher efficiency is achieved at low displacements with PSPP. While other systems have implemented PSPP with electric or cam-actuated valves, the pump described in this paper is unique in implementing PSPP by way of a simple, robust hydro-mechanical valve system. Experimental testing of a prototype PSPP pump/motor shows that the full load efficiency is maintained even at low displacements.