scholarly journals Design and construction of multi-cylinder type liquid piston Stirling engine

2021 ◽  
Vol 313 ◽  
pp. 08003
Author(s):  
Prastowo Murti ◽  
Akira Takizawa ◽  
Eita Shoji ◽  
Tetsushi Biwa
Keyword(s):  
Preliminary Test ◽  
Acoustic Power ◽  
Stirling Engine ◽  
Geometrical Parameters ◽  
Test Results ◽  
Operation Temperature ◽  
Mass Spring Model ◽  
Mass Spring ◽  
Liquid Piston

In a multi-cylinder type liquid piston Stirling engine (MCLPSE), liquid columns in U-shaped tubes play the role of solid pistons in a mechanical Stirling engine. Besides the straightforward structure, advantages of the MCLPSE are a relatively low operation temperature difference below 100 K and use of harmless working fluids of air and water. This study presents a mass spring model for the MCLPSE, from which we determine geometrical parameters of MCLPSE to achieve a target acoustic power production under a given temperature condition. The preliminary test results will be presented.

INVESTIGATING THE EFFECT OF SLOSHING ON THE ENERGY ABSORPTION OF TANK WAGONS CRASH

2015 ◽  
Vol 39 (2) ◽  
pp. 187-200 ◽  
Author(s):  
Reza Razaghi ◽  
Majid Sharavi ◽  
Mohammad Mahdi Feizi
Keyword(s):  
Energy Absorption ◽  
Solution Method ◽  
Crash Test ◽  
Test Results ◽  
Software Simulation ◽  
Fluid Sloshing ◽  
Mass Spring Model ◽  
Solution Methods ◽  
Height Increase ◽  
Mass Spring

One of the main fluid mechanics phenomena is fluid sloshing which is originated from the free surface of fluid and should be taken into account in design of fluid structures such as fuel tank wagons, ships and so on. The aim of this paper is to investigate the effect of tank fluid sloshing on energy absorption and reducing tank acceleration during the tank wagon impact. For this purpose, methods of software simulation and dynamics solution methods are accomplished. The assumed wagon includes a tank with the approximate volume of 95 m3 and capacity of 65 tons of fluid. Using finite element method, the tank impact is simulated based on the corresponding standards for different heights of fluid in the tank. Obtained results show fluid height increase has an inappropriate effect on energy absorption among impact however the more fluid in tank, the more time would be consumed for energy absorption in general. At the end, by using crash test results for a tank with aforementioned scale, validity of impact software simulation and dynamic solution method considering the tank fluid as mass-spring model are checked.

NONLINEAR RESPONSE OF THE MASS-SPRING MODEL WITH NONSMOOTH STIFFNESS

2012 ◽  
Vol 22 (01) ◽  
pp. 1250006 ◽  
Author(s):  
GRZEGORZ LITAK ◽  
JESÚS M. SEOANE ◽  
SAMUEL ZAMBRANO ◽  
MIGUEL A. F. SANJUÁN
Keyword(s):  
Nonlinear Response ◽  
Homoclinic Orbits ◽  
Prototype Model ◽  
Spring Model ◽  
Mass Spring Model ◽  
Nonlinear Potential ◽  
Melnikov Analysis ◽  
Linear Spring ◽  
Mass Spring

In this paper, we study the nonlinear response of the nonlinear mass-spring model with nonsmooth stiffness. For this purpose, we take as prototype model, a system that consists of the double-well smooth potential with an additional spring component acting on the system only for large enough displacement. We focus our study on the analysis of the homoclinic orbits for such nonlinear potential for which we observe the appearance of chaotic motion in the presence of damping effects and an external harmonic force, analyzing the crucial role of the linear spring in the dynamics of our system. The results are shown by using both the Melnikov analysis and numerical simulations. We expect our work to have implications on problems concerning the suspension of vehicles, among others.

scholarly journals Design of a Low-Cost Thermoacoustic Electricity Generator and Its Experimental Verification

2010 ◽  
Author(s):  
Zhibin Yu ◽  
Artur J. Jaworski ◽  
Scott Backhaus
Keyword(s):  
Experimental Verification ◽  
Low Cost ◽  
Preliminary Test ◽  
Detailed Comparison ◽  
Acoustic Power ◽  
Travelling Wave ◽  
Test Results ◽  
Thermoacoustic Engine ◽  
Design And Testing ◽  
Different Parts

This paper describes the design and testing of a low cost thermoacoustic generator. A travelling-wave thermoacoustic engine with a configuration of a looped-tube resonator is designed and constructed to convert heat to acoustic power. A commercially available, low-cost loudspeaker is adopted as the alternator to convert the engine’s acoustic power to electricity. The whole system is designed using linear thermoacoustic theory. The optimization of different parts of the thermoacoustic generator, as well as the matching between the thermoacoustic engine and the alternator are discussed in detail. A detailed comparison between the preliminary test results and linear thermoacoustic predictions is provided.

Tuning of Bandgap Structures in Three-Dimensional Kagome-Sphere Lattice

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Ying Liu ◽  
Xiu-zhan Sun ◽  
Wen-zheng Jiang ◽  
Yu Gu
Keyword(s):  
Phononic Crystal ◽  
Three Dimensional ◽  
Structure Design ◽  
Geometrical Parameters ◽  
Geometrical Condition ◽  
Mass Spring Model ◽  
Sphere Radius ◽  
Equivalent Mass ◽  
Kagome Truss ◽  
Mass Spring

In this manuscript, acoustic wave propagation in a novel three-dimensional porous phononic crystal-Kagome lattice, is studied by using finite element method. Firstly, a Kagome-sphere structure is established based on Kagome truss. For lattice with fixed rods (sphere radius varied) or fixed spheres (rod radius varied), the band structures are calculated in order to clarify the influence of geometrical parameters (sphere and rod sizes) on the bandgap characteristics in Kagome-sphere lattice. The vibration modes at the band edges of the lowest bandgaps are investigated with the aim to understand the mechanism of the bandgap generation. It is found that the emergence of the bandgap is due to the local resonant vibration of the unit cell at the adjacent bands. The width and position of this bandgap can be tuned by adjusting the geometrical parameters. An equivalent mass-spring model is proposed and the equivalent system resonance frequency can be evaluated which predicts well the upper and lower edges of the complete bandgaps. Moreover, the critical geometrical parameter is formulated which gives the critical geometrical condition for the opening of the complete bandgaps. The results in this paper are relevant to the bandgap structure design of three-dimensional porous phononic crystals (PPCs).

A Study on the Parameters Influencing Clearance of Mucus During Cough in a Model Trachea

2011 ◽  
Author(s):  
Anpalaki J. Ragavan ◽  
Cahit A. Evrensel ◽  
Peter Krumpe
Keyword(s):  
Preliminary Test ◽  
Geometrical Parameters ◽  
Test Results ◽  
Independent Variables ◽  
Dimensional Group ◽  
Large Numbers ◽  
Rigid Model ◽  
Airway Mucus ◽  
Human Airways

There are large numbers of physiological, material and geometrical parameters that influence the efficiency of clearance of mucus by cough in human airways. In this study the effect of ten independent variables on the displacement of simulated airway mucus in a rigid model trachea during cough is explored. This is the first attempt in combining these 10 parameters into a single non-dimensional group. Eight hundred (800) different combinations of these parameters are used to test its feasibility experimentally. All independent variables had variance inflation less than 10 indicating adequate independence among them. Although additional tests may be needed to confirm, the preliminary test results are promising.

PHASE CONTROL IN THE MASS-SPRING MODEL WITH NONSMOOTH STIFFNESS AND EXTERNAL EXCITATION

2013 ◽  
Vol 23 (12) ◽  
pp. 1330042 ◽  
Author(s):  
MATTIA COCCOLO ◽  
JESÚS M. SEOANE ◽  
GRZEGORZ LITAK ◽  
MIGUEL A. F. SANJUÁN
Keyword(s):  
Chaotic Dynamics ◽  
Phase Control ◽  
Control Technique ◽  
Prototype Model ◽  
Spring Model ◽  
Mass Spring Model ◽  
Melnikov Analysis ◽  
Mass Spring ◽  
Double Well Potential

The control of chaotic dynamics in a nonlinear mass-spring model with nonsmooth stiffness is analyzed here. This is carried out by applying the phase control technique, which uses a periodic perturbation of a suitable phase ϕ. For this purpose, we take as prototype model a system consisting of a double-well potential with an additional spring component, which acts into the system only for large enough displacements. The crucial role of the phase is evidenced by using numerical simulations and also by using analytical methods, such as the Melnikov analysis. We expect that our results might be fruitful with implications in some mechanical problems such as suspension of vehicles, among others, where similar models are extensively used.

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