摘要:

AbstractAn implicit spatial differencing technique with fourth‐order accuracy has been developed based on the Pade compact scheme. A dispersion‐relation‐preserving concept has been incorporated into the numerical scheme. Two‐dimensional Euler computation of a spatially developing free shear flow with and without external excitation has been performed to demonstrate the capability of the numerical scheme developed. Results are in good agreement with theory and experimental observation regarding the growth rate of the fluctuating velocity, the convective velocity and the vortex‐pairing process. The far‐field sound pressure generated by the computed shear flow solution using Lighthill's acoustic analogy shows a strong directivity with a zone of silence at the

ISSN:0271-2091    

DOI:10.1002/fld.1650180403

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractIn stratified three‐dimensional models the use of a boundary‐fitted vertical co‐ordinate is known to produce errors in the horizontal pressure gradient calculation near steep topography. The error is due to the splitting of the horizontal pressure gradient term in each of the momentum equations into two parts and the subsequent incomplete cancellation of the truncation errors of those parts. In order to minimize these pressure gradient errors, a fourth‐order‐accurate pressure gradient calculation has been implemented and installed in SPEM, a three‐dimensional primitive equation ocean model. The stability and accuracy of the new scheme are compared with those of the original second‐order‐accurate model in a series of calculations of unforced flow in the vicinity of an isolated seamount. The new scheme is shown to have much smaller pressure gradient errors over a wide range of parameter space as well as a greater parametric domain of nume

ISSN:0271-2091    

DOI:10.1002/fld.1650180404

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe aim of the present study is to examine the accuracy and improvement of various numerical methods in the solution of the transonic shock/turbulent boundary layer interaction problem and to show that a significant source of numerical inaccuracies in turbulent flows is not only the inadequacy of the turbulence model but also the numerical discretization. Comparisons between a Riemann solver and a flux‐vector‐splitting method as well as between various numerical high‐order extrapolation schemes with corresponding experimental results are pres

ISSN:0271-2091    

DOI:10.1002/fld.1650180405

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe axial singularity inverse method for designing bodies of revolution has been improved by using higher‐order doublet elements. The performance of the method for various element orders and other solution parameters is presented in detail. The results indicate that the method is generally more robust, less sensitive to insets and has a better‐conditioned coefficient matrix compared with the source method of the same order. The condition number of the matrix is shown to increase with the thickness of the body, the order of the method, the number of elements and the degree of stretching of the node distribution. In general, good performance is attained for most bodies even with ƒras low as 2 by using 10–12 second‐order doublet elements with insets greater than 0.02Lfrom rounded ends. Increasing the insets to 0.06Lappears to improve the accuracy of the method for most bodies but slows its con

ISSN:0271-2091    

DOI:10.1002/fld.1650180406

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650180407

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650180402

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY