Experimental investigations of the externally heated valve engine model

Author(s):  
L Brzeski ◽  
Z Kazimierski

The experimental investigations of the first model of the externally heated valve engine carried out during 1998-9 are the subject of this paper. The working gas of the engine is air. A detailed description of the engine equipped with two consecutively working heaters is given. Two kinds of heaters were constructed and investigated. The experimental stand and the measurement system are described. In this first stage of the engine investigation, electric radiators were used as the external source of heat. The main aim of the experimental investigations was focused on measurements of time-dependent pressures inside the expander and compressor cylinders. The pressures were measured by means of two kinds of pressure transducers (piezoresistive and piezoelectric) to get confidence in the obtained results. The conducted investigations prove that The engine model has an operating ability. Comparisons of the experimental and theoretical pressures inside the expander and compressor show a satisfactory agreement. It confirms that the engine operates according to the original thermodynamical cycle and exhibits the internal power and efficiency predicted by the computer simulation. The experiences gained during these investigations have been used to modify the engine model, which is outlined in this paper.

1981 ◽  
Vol 18 (2) ◽  
pp. 561-567 ◽  
Author(s):  
J. Michael Harrison ◽  
Austin J. Lemoine

The subject of this paper is networks of queues with an infinite number of servers at each node in the system. Our purpose is to point out that independent motions of customers in the system, which are characteristic of infinite-server networks, lead in a simple way to time-dependent distributions of state, and thence to steady-state distributions; moreover, these steady-state distributions often exhibit an invariance with regard to distributions of service in the network. We consider closed systems in which a fixed and finite number of customers circulate through the network and no external arrivals or departures are permitted, and open systems in which customers originate from an external source according to a Poisson process, possibly non-homogeneous, and each customer eventually leaves the system.


1981 ◽  
Vol 18 (02) ◽  
pp. 561-567 ◽  
Author(s):  
J. Michael Harrison ◽  
Austin J. Lemoine

The subject of this paper is networks of queues with an infinite number of servers at each node in the system. Our purpose is to point out that independent motions of customers in the system, which are characteristic of infinite-server networks, lead in a simple way to time-dependent distributions of state, and thence to steady-state distributions; moreover, these steady-state distributions often exhibit an invariance with regard to distributions of service in the network. We consider closed systems in which a fixed and finite number of customers circulate through the network and no external arrivals or departures are permitted, and open systems in which customers originate from an external source according to a Poisson process, possibly non-homogeneous, and each customer eventually leaves the system.


1997 ◽  
Vol 67 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Rangaswamy Rajamanickam ◽  
Steven M. Hansen ◽  
Sundaresan Jayaraman

A computer simulation approach for engineering air-jet spun yarns is proposed, and the advantages of computer simulations over experimental investigations and stand-alone mathematical models are discussed. Interactions of the following factors in air-jet spun yarns are analyzed using computer simulations: yarn count and fiber fineness, fiber tenacity and fiber friction, fiber length and fiber friction, and number of wrapper fibers and wrap angle. Based on the results of these simulations, yarn engineering approaches to optimize strength are suggested.


2012 ◽  
Vol 588-589 ◽  
pp. 1337-1340
Author(s):  
Y.X. Zhu ◽  
X.S. Duan

For the pose measurement of cannon barrel, a vision method through checked plane had been proposed. To test and improve the precision of this new method without considering the hardware error and some other inextricable objective factors,derive the imaging model of the marker (checked plane) from motion model of cannon barrel and the position relative to it using variable-controlling method. Establish the computer simulation platform of vision measurement system for cannon barrel pose based on C++ Builder. The simulation experiment validate the veracity and dependability of this method.


2008 ◽  
Vol 385-387 ◽  
pp. 381-384 ◽  
Author(s):  
Wei Wang ◽  
Hua Ling ◽  
Xiao Ni Wang ◽  
Tian Xia ◽  
Da Zhi Wang ◽  
...  

With the increase in the use of recycled aggregate concrete (RAC), it is necessary to clearly understand its behavior and characteristics. In this paper, experimental study on compressive strength of RAC with same water/cement ratio is conducted. Firstly, influence of recycled coarse aggregate contents on cube compressive strength of RAC is studied. Secondly, experiment on time-dependent strength developing process of RAC is conducted with different solidification ages. Finally, based on above experimental investigations, empirical formula for compress strengths of RAC with different ages is presented. The result of this paper is helpful to theoretical analysis and practical engineering design of RAC structures.


1985 ◽  
Vol 22 (03) ◽  
pp. 503-517
Author(s):  
Helmut Pruscha

The present paper deals with continuous-time Markov branching processes allowing immigration. The immigration rate is allowed to be random and time-dependent where randomness may stem from an external source or from state-dependence. Unlike the traditional approach, we base the analysis of these processes on the theory of multivariate point processes. Using the tools of this theory, asymptotic results on parametric inference are derived for the subcritical case. In particular, the limit distributions of some parametric estimators and of Pearson-type statistics for testing simple and composite hypotheses are established.


2017 ◽  
Vol 4 ◽  
pp. 104-107
Author(s):  
Sławomir Bronisz ◽  
Elżbieta Miłosz

The article presents the results of research on the analysis of the possibilities of using the Moodle platform for the implementation of the education process at the engineering systems of internal security in the Lublin University of Technology. The research involved an analysis of the possibility of Moodle and computer simulation of the subject of Information Technologies.


When a beam of electric particles is passed through a sheet of matter the energy of the individual particles is reduced. The loss of energy is not the same for all the particles so that particles incident on the foil with the same energy emerge with different energies. This dispersion of the energy caused by the foil is known as the "straggling" of the particles. The straggling of α-particles has been the subject of several experimental investigations, and the theory in this case was adequately developed by Bohr in 1915. In the case of β-particles, however, the straggling was not experimentally investigated until quite recently and no theoretical treatment of the phenomenon has been given, the calculations of Bohr being, as he showed, applicable only to α-particles. The purpose of the work described in this paper is to develop a theory of the straggling of β-particles by thin foils and by means of it to interpret the results of experiment. The paper is arranged as follows. In 2 an account is given of the state of the experimental work on the subject, and in particular the effect of the complications introduced by "scattering" are considered. The formula derived by Bohr for the straggling of electric particles is given in 3 and its inapplicability to β-particles demonstrated. The present calculations of the straggling of β-particles are given in 4. The theory of the straggling of electric particles resolves itself into two parts. The first deals with the dynamics of collisions between electric particles and atoms, and is the same whether we are concerned with the straggling or some other phenomena such as ionisation of "stopping power." This may be called the fundamental theory and its requirements may be summarised in the function ϕ (Q) which express the frequency of collisions in which the electric particle loses energy of amount Q. The second part of the theory is the process of calculating the straggling by means of probability theory from the function ϕ . This may be regarded as the straggling theory proper and it is the main subject of 4. When the present calculations were started it was intended to calculate the straggling on the basis of classical theory only, the value of the function ϕ on this theory being definitely known. However, after some practice with the type of calculation involved it was decided to calculate the straggling for other forms of ϕ . From the results obtained it is possible to deduce the straggling corresponding to any form which ϕ may reasonably have, and if a new theory leads to a value of ϕ different from the classical value, the straggling on the new theory may readily be determined. Alternatively this fuller treatment may be used for the reverse process of calculating from the observed straggling the value of ϕ to which it corresponds. This is considered to be the most convenient procedure and in 5 the form of ϕ which explains the experimental results is deduced. this is compared in 6 with the value of ϕ on classical theory. A brief outline is given in 7 of certain new ideas concerning the nature of collisions of electric particles with electrons and atoms.


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