The paper describes the identification of the variable critical gain and natural frequency of the pneumatic cylinder using the self-excited oscillations method. The pneumatic drives are characterized by the low stiffness of the pneumatic cylinder which depends on the piston position and determines the natural frequency of the cylinder. The variety of the stiffness in dependence on the piston po...

This paper proposes an approach for optimal design of multilevel systems under uncertainty. The approach utilizes the stochastic extension of the analytical target cascading formulation. The reliability of satisfying the probabilistic constraints is computed by means of the most probable point method using the hybrid mean value algorithm. A linearization technique is employed for estimating the...

PURPOSE Palpation is used most commonly to assess tissue stiffness despite its well-known deficiencies. As an improvement, a mechanical technique known as ultrasonic indentation has been proposed. The purpose of this study was to compare the accuracy of 3 ultrasonic indentation techniques in quantifying bone displacement in a specially constructed tissue simulator. METHODS Three ultrasonic in...

Manufacturing produces real wealth for any country and constitutes the back bone for the service sector. The objective of any organization is to earn profit. Usually the market fixes the selling price of the manufactured components. Unless there is focus on the manufacturing strategy of reducing manufacturing cost, it is very difficult to sustain in this ever competitive world. A suitable manuf...

The goal of this project is to provide a compact and efficient fluid power source for mobile applications (10 kW-500 kW), including on-road vehicles and off-road heavy machineries. This is achieved through the development of a hydraulic free-piston engine (HFPE). Previously, a virtual crankshaft mechanism is proposed by the authors which regulates the pistons to follow any reference trajectorie...

The gas force due to the combustion in the cylinder of an IC engine will cause the piston to move with primary motion and secondary motion. The primary motion of the piston from TDC to BDC is linear in nature. This motion is desired for translation of motion of engine components. Secondary motion is due to the transverse motion of the piston while piston moving from TDC to BDC and vice-versa. T...

This work proposes a new configuration of liquid piston compressors and methodology for their optimization, with special attention to heat removal from the compressing gas, in order minimize mechanical required compression process. The adopted approach starts solution governing equations through 0D model (lumped approach). A correlation transfer coefficient is presented calculate sensible gas c...

By theoretically analyzing dynamic behavior of the crankshaft, the rolling piston and the blade inrolling-piston rotary compressors, constraint forces and sliding speed at each pair of movable machine elements were obtained, and unbalanced inertia forces and compressor vibrations were evaluated. It was concluded that theoretical results have a goodagreement with experimental ones. Moreover, it ...

Various analysis to calculate the thermodynamic efficiency, the performances of the valve systems and the acoustic characteristics of the gas manifold are integrated in one system with necessary design rules for basic design of compressors. Expert system rule bases are used to identify design problems existing in the model and to suggest directions to improve them. A case study illustrates how ...

This paper takes dynamics analysis on the piston and the dynamic lubrication theory on the skirt and the ring of piston as the basis. Using AVL Glide software, through the establishment of the analysis model of the piston secondary movements, this study focuses on the effects of the crankshaft bias on piston secondary movements’ characteristics. This paper takes 5 different offsets, by comparin...