Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    A parallelized eno procedure for direct numerical simulation of compressible turbulence (1996)
    Springer
    Journal of scientific computing 11 (1996), S. 179-205 
    Details
    ISSN: 1573-7691
    Keywords: Compressible flows ; direct numerical simulation ; essentially non-oscillatory ; parallel processing ; turbulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In this paper, a finite-difference based ENO (essentially nonoscillatory) procedure has been chosen for the direct numerical simulation (DNS) of compressible turbulence. The implementation of the ENO scheme follows the relatively efficient procedure in Shuet al. (1992), but the latter has been modified in the present paper to admit scalar conservation equations and to run on the iPSC/860 Paragon parallel supercomputer. DNS results with our procedure are in excellent agreement with pseudo-spectral and Padé approximation calculations in two and three dimensions. This is the case for a variety of initial conditions for compressible turbulence. The parallel algorithms presented are simple but quite efficient for DNS, with a speedup that approaches the theoretical value. Some of the attractive features include 1) minimum communication whereby a processor only communicates with two neighbors, 2) almost one hundred percent load balancing, 3) a checker-board approach to solve the Poisson equation reduces communication by a factor of approximately 2, and, 4) obtaining turbulence statistics is based on a ‘global collect’ approach, which is implemented to ensure that a single number, rather than a large matrix of numbers, is communicated between processors. The ENO code presented in this paper should be quite useful in its own right, while the parallel implementation should allow the simulation of fairly realistic problems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02088815
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Characterization of epoxy-surfactant interactions (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 36 (1998), S. 2781-2792 
    Details
    ISSN: 0887-6266
    Keywords: waterborne epoxy ; surfactant ; cooperativity ; Fox equation ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: We have investigated epoxies based on the diglycidyl ether of bisphenol A (DGEBA) cured with 2-ethyl-4-methylimidazole (EMI-24) in the presence of the nonionic surfactant Triton X-100. A goal was to determine if the viscoelastic properties of the epoxy-surfactant system differed when prepared in bulk form, as opposed to being cast as a thin film on the surface of E-glass cloth. Such a combination of materials has generated great interest for potential use in the construction of laminated circuit boards. Using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and atomic force microscopy (AFM), it was determined that the surfactant acts as a plasticizer and is miscible with the epoxy system in concentrations up to 15% by weight. The glass transition temperature (Tg) depression of the epoxy due to the surfactant was accurately described by the Fox equation. DMA master curves were constructed in the frequency domain. The temperature dependence of the shift factors was used to determine the fragility of each of the samples studied. It was found that the fragility (cooperativity) of the epoxy decreased as the concentration of surfactant increased, presumably due to a reduction of intermolecular constraints. The fragility of the combined epoxy-surfactant system increased when cast on the surface of the E-glass cloth. Results for our model epoxy-surfactant resin were in excellent agreement with those obtained using a commercially available aqueous waterborne epoxy resin. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 2781-2792, 1998
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...