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Showing papers by "Nanjing University of Science and Technology published in 1993"


Journal ArticleDOI
TL;DR: In this article, the dispersion model is applied to the description of the effects of shell and tubeside flow maldistribution, and an efficient and versatile method of predicting transient response of multipass shell and tube heat exchangers is developed.

21 citations


Proceedings ArticleDOI
10 Dec 1993
TL;DR: This paper presents a new algorithm, the overlapping averaging 4-frame (OAF) algorithm, which can reduce the phase error due to phase shifter errors, which is more highly accurate than other phase-measurement algorithms.
Abstract: Phase shifting interferometry (PSI) is a highly efficient and accurate phase measuring method. The accuracy of PSI is most seriously impaired by calibration error and nonlinearity in the phase shifter. This paper presents a new algorithm, the overlapping averaging 4-frame (OAF) algorithm, which can reduce the phase error due to phase shifter errors. The relationship between the accuracy of OAF algorithm and phase shifter errors is given. From this relationship, it is verified that the OAF algorithm can reduce the phase error due to phase shifter errors. The computer simulation providing the magnitude of a calibration error and nonlinearity in the phase shifter are shown for a number of different phase-measurement algorithms. From the analysis, the result is obtained that the OAF algorithm is more highly accurate than other phase-measurement algorithms.

13 citations


Journal ArticleDOI
TL;DR: In this paper, a method of predicting the transient behavior of parallel and counterflow heat exchangers is developed, whereby the effects of shell-side flow maldistribution and the finite heat capacities of both fluids, tube bundle and shell are considered.
Abstract: Based on the dispersion model rather than on the conventional plug-flow model, a method of predicting the transient behaviour of parallel and counterflow heat exchangers is developed, whereby the effects of shell-side flow maldistribution and the finite heat capacities of both fluids, tube bundle and shell are considered. The final solution has been obtained by numerical inversion of the Laplace transform, to determine the transient responses to arbitrary inlet temperature variations. The experiment was carried out in a one pass tube heat exchanger. The comparison between theoretical and experimental results is presented and the feasibility of this method is discussed

6 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of radial heat conduction in tube and shell walls as well as heat loss from the shell to the environment has been investigated and a predicting method for transient behavior of counter and parallel heat exchangers is developed.

4 citations


Proceedings ArticleDOI
30 Jul 1993
TL;DR: In this paper, the relative density profiles at the transition region in the boundary layer on a 200 cone model of the hypersonic shock tunnel were calculated by means of computer image processing technique.
Abstract: In this paper, the application of a large aperture and high sensitivity moire interfer-ometer in visualization of the boundary layer transition on a model in the hypersonic shocktunnel is presented experimentally and the measurement principles are described theoreti-cally. By means of the computer image processing technique, the relative density profilesat the transition region in the boundary layer on a 200 cone model is calculated quantitative-ly. The freestream conditions in the hypersonic shock tunnel are M = 10. 29, Re/L = 1. 38

3 citations


Proceedings ArticleDOI
30 Jul 1993
TL;DR: In this article, the authors propose a method to solve the problem of unstructured data. But it requires not available data sets, which is not available in this paper, and
Abstract: Abstract not available.

3 citations


Proceedings ArticleDOI
10 Dec 1993
TL;DR: In this article, a large-aperture high-accuracy phase-shifting digital flat interferometer which is a combination of optic, mechanics, electricity, and algorithm is described.
Abstract: This paper describes a large-aperture high-accuracy phase-shifting digital flat interferometer which is a combination of optic, mechanics, electricity, and algorithm. The aperture size is 250 mm and liquid surface is used as an absolute flat to eliminate systemic error. The accuracy is better than (lambda) /50 ((lambda) is Hz-Ne laser wavelength) (peak-to-valley value). The tested aperture can be enlarged to 500 mm. This interferometer will be used as our country optical flat standard instrument. This paper describes the optical interferometer, phase shifter, and calibration of precision.

2 citations


Proceedings ArticleDOI
10 Dec 1993
TL;DR: This paper discusses the development of a new technique for testing larger optical flat only by means of a smaller interferometer, an overlapping subaperture interference testing (OSIT) technique, which has established a mathematics model for OSIT to retrieve the surface of the full aperture.
Abstract: This paper discusses the development of a new technique (including theory, method, and equipment, etc.) for testing larger optical flat only by means of a smaller interferometer. It is an overlapping subaperture interference testing (OSIT) technique. The author has established a mathematics model for OSIT to retrieve the surface of the full aperture. The theoretical accuracy of the retrieved surface of the full aperture reached (lambda) /200 (p-v). The relationship between the accuracy of the retrieved wavefront of full aperture and errors (such as system error of interferometer or position error of subapertures, etc.) has been investigated. A computer program was established to simulate the real procedure from testing surface data of subaperture to retrieved wavefront of full aperture.

1 citations


Proceedings ArticleDOI
10 Dec 1993
TL;DR: In this article, the phase shifting error introduced by a phase shifter is reduced using overlapping averaging four-frame algorithm, and a standard plano-convex lens is tested to verify the accuracy of this technique.
Abstract: An automatic technique to process Ronchigrams is presented. The phase shifting error introduced by a phase shifter is reduced using overlapping averaging four-frame algorithm. A standard plano-convex lens is tested to verify the accuracy of this technique.

1 citations


Proceedings ArticleDOI
06 Sep 1993
TL;DR: In this summary, a mini review is given by emphasizing the uniform understanding of different methods in field-theory solution in microwaves and some progress on these aspects especially made by the author and his colleagues is introduced.
Abstract: A talent of effective field-theory solution is one of the most important assets for the scientists and engineers working in the areas of microwave integrated circuits, optical integrated circuits, electromagnetic compatibility and so on. In this summary, a mini review is given by emphasizing the uniform understanding of different methods in field-theory solution in microwaves. Some progress on these aspects especially made by the author and his colleagues is introduced.

Journal ArticleDOI
TL;DR: Theoretical calculations on the hydrolyses of dinitro semi-glycoluril in neutral, acidic and alkaline media, have been performed by using AMI method.
Abstract: Theoretical calculations on the hydrolyses of dinitro semi-glycoluril in neutral, acidic and alkaline media, have been performed by using AMI method. The geometries of reactant, activated, and product complex for the hydrolysis processes have been fully optimized. Both in neutral and acidic media, activated complexes with four-membered ring structure have been obtained, and reaction-coordinate eigenvectors reveal their concerted feature of component processes involved. In contrast, in alkaline media, the hydrolysis is relatively easy, since it proceeds without activation of reactant complex, and the potential energy curve of this hydrolysis process obtained is also indicative of this. The calculated activation energies for the hydrolyses of dinitro semi-glycoluril in neutral and acidic media are 217. 233 kJ/mol and 218. 856 kJ/mol respectively.

Proceedings ArticleDOI
19 Oct 1993
TL;DR: An object-oriented distributed transaction in the HDOOM model is implemented, built on the base of a Novell LAN, and the transaction structure and implementation is described.
Abstract: Distributed transactions are an important programming paradigm for simplifying the construction of reliable and available distributed applications. We have implemented an object-oriented distributed transaction in the HDOOM model. This model is built on the base of a Novell LAN. The transaction facilities are provided as a routine library in C++. This adds parallel and atomic features to the C++ language. This paper presents the object model HDOOM, and describes the transaction structure and implementation. >