Generation of Surface Coordinates by Elliptic Partial Differential Equations

The problem of generating spatial coordinates by numerical methods through carefully selected mathematical models is of current interest both in mechanics and physics. The problem of generation of a desired system of coordinates in a given surface was considered, which essentially is an effort directed to the problem of grid generation in a two-dimensional non-Euclidean space. The mathematical model selected for this purpose is based on the formulae of Gauss for a surface. The proposed equations can be used to generate a new coordinate system from the data of an already given coordinate system in a surface. If the coefficients of the first and second fundamental forms have been given, then the proposed equations can be used to generate a surface satisfying the given data (surface fitting). The proposed equations can also be used to generate surfaces in the space between two arbitrary given surfaces, thus providing 3D grids in an Euclidean space

User's guide to PMESH: A grid-generation program for single-rotation and counterrotation advanced turboprops

A detailed operating manual is presented for a grid generating program that produces 3-D meshes for advanced turboprops. The code uses both algebraic and elliptic partial differential equation methods to generate single rotation and counterrotation, H or C type meshes for the z - r planes and H type for the z - theta planes. The code allows easy specification of geometrical constraints (such as blade angle, location of bounding surfaces, etc.), mesh control parameters (point distribution near blades and nacelle, number of grid points desired, etc.), and it has good runtime diagnostics. An overview is provided of the mesh generation procedure, sample input dataset with detailed explanation of all input, and example meshes

Numerical generation of two-dimensional orthogonal curvilinear coordinates in an Euclidean space

A noniterative method for the numerical generation of orthogonal curvilinear coordinates for plane annular regions between two arbitrary smooth closed curves was developed. The basic generating equation is the Gaussian equation for an Euclidean space which is solved analytically. The method is applied in many cases and these test results demonstrate that the proposed method can be readily applied to a wide variety of problems. The method can also be used for simply connected regions only by obtaining the solution of the linear equation under the changed boundary conditions

Quality of Medical Information Determine the Quality of Diagnosis Code

The accuracy of the diagnosis code has implications for future patient care planning, provision of health services and patient care costs. Therefore, this study has analyzed the influence of the quality of medical information on the quality of the diagnosis code which includes the accuracy, consistency, completeness and timeliness in coding the diagnosis of inpatients at Dr. Moewardi hospital.This was an observational analytic study with a sample of 250 medical records taken using stratified random sampling. Data were analyzed by chi square test. High quality of medical information has a better diagnosis code quality (73.80%) compared to poorly quality of medical information (36.00%). High quality of medical information has a log odds of 1.54 better in the quality of diagnosis code than poorly quality of medical information (b=1.54; 95% CI=0.81-2.27, p<0.001)

Numerical solution of the Navier-Stokes equations for blunt nosed bodies in supersonic flows

A time dependent, two dimensional Navier-Stokes code employing the method of body fitted coordinate technique was developed for supersonic flows past blunt bodies of arbitrary shapes. The bow shock ahead of the body is obtained as part of the solution, viz., by shock capturing. A first attempt at mesh refinement in the shock region was made by using the forcing function in the coordinate generating equations as a linear function of the density gradients. The technique displaces a few lines from the neighboring region into the shock region. Numerical calculations for Mach numbers 2 and 4.6 and Reynolds numbers from 320 to 10,000 were performed for a circular cylinder with and without a fairing. Results of Mach number 4.6 and Reynolds number 10,000 for an isothermal wall temperature of 556 K are presented in detail

Numerical solutions for laminar and turbulent viscous flow over single and multi-element airfoils using body-fitted coordinate systems

The technique of body-fitted coordinate systems is applied in numerical solutions of the complete time-dependent compressible and incompressible Navier-Stokes equations for laminar flow and to the time-dependent mean turbulent equations closed by modified Kolmogorov hypotheses for turbulent flow. Coordinate lines are automatically concentrated near to the bodies at higher Reynolds number so that accurate resolution of the large gradients near the solid boundaries is achieved. Two-dimensional bodies of arbitrary shapes are treated, the body contour(s) being simply input to the program. The complication of the body shape is thus removed from the problem

A high-level computing algorithm for diverging and converging branch nonserial dynamic programming systems

AbstractWe present high-level computing algorithms for efficiently processing the diverging and converging branch systems in nonserial dynamic programming. A special technique in devised for processing the network functions such that the minimum amount of storage is employed. It is shown that if k is the discretization level of the state and decision variables then the space complexities are O(k) and O(k2) for the diverging and converging branch systems, respectively. The resultant time complexities are also developed. These savings in computational complexities enhance the attractiveness of dynamic programming as a tool for processing more complex nonserial systems

Fuzzy automata and pattern matching

A wide-ranging search for articles and books concerned with fuzzy automata and syntactic pattern recognition is presented. A number of survey articles on image processing and feature detection were included. Hough's algorithm is presented to illustrate the way in which knowledge about an image can be used to interpret the details of the image. It was found that in hand generated pictures, the algorithm worked well on following the straight lines, but had great difficulty turning corners. An algorithm was developed which produces a minimal finite automaton recognizing a given finite set of strings. One difficulty of the construction is that, in some cases, this minimal automaton is not unique for a given set of strings and a given maximum length. This algorithm compares favorably with other inference algorithms. More importantly, the algorithm produces an automaton with a rigorously described relationship to the original set of strings that does not depend on the algorithm itself

Computational Fluid Dynamic (CFD) analysis of axisymmetric plume and base flow of film/dump cooled rocket nozzle

Film/dump cooling a rocket nozzle with fuel rich gas, as in the National Launch System (NLS) Space Transportation Main Engine (STME), adds potential complexities for integrating the engine with the vehicle. The chief concern is that once the film coolant is exhausted from the nozzle, conditions may exist during flight for the fuel-rich film gases to be recirculated to the vehicle base region. The result could be significantly higher base temperatures than would be expected from a regeneratively cooled nozzle. CFD analyses were conduced to augment classical scaling techniques for vehicle base environments. The FDNS code with finite rate chemistry was used to simulate a single, axisymmetric STME plume and the NLS base area. Parallel calculations were made of the Saturn V S-1 C/F1 plume base area flows. The objective was to characterize the plume/freestream shear layer for both vehicles as inputs for scaling the S-C/F1 flight data to NLS/STME conditions. The code was validated on high speed flows with relevant physics. This paper contains the calculations for the NLS/STME plume for the baseline nozzle and a modified nozzle. The modified nozzle was intended to reduce the fuel available for recirculation to the vehicle base region. Plumes for both nozzles were calculated at 10kFT and 50kFT

PENJADWALAN EKONOMIS PEMBANGKIT TERMAL MENGGUNAKAN METODA ITERASI LAMBDA DENGAN MEMPERHITUNGKAN RUGI-RUGI SALURAN

. Pembangkit-pembangkit menyuplai dayA untuk memeNuhi kebutuhan beban pada suatu sistem tenaga. Sistent-sistem kecil sering dijumpai hanya menggunakan pembangkit-penbangkit termal saja untuk melayani kebutuhan beban sistem itu, misalnya pada perusahaan-perusahaan yang daerah operasinya luas atau pulau-pulau yang tidak memiliki sumber daya lain. Setiap pembangkit memiliki karaheristik biaya, harga bahan baksr dan limit yang berbeda serra jarak masing-masingnya terhadap pusat beban, sehinggo perlu d;t'akukan suatu perrtbagian pembangkitan daya oleh pembangkit-pembangkir tersebut dengan mempertimbangkan rugi-rugi trcutsmisi untuk mendapatkan total biaya pembangkitan yong ekonomis. Upaya ini dikenal dengan penjadwalan ekonomis. Salah satu metoda yang digunakan untuk perhitungan penjadwalan ekonomis adalah metoda iterasi lambda. Metoda ini cepat dalam mencapai konvergensi karena lambda mual yang diberikan adalah lambda perhitungan penjadwalan ekonomis tanpa rugi-rugi transmisi. Pada tugas akhir ini dirancang suatu program komputer untuk menghitung penjadwalan ekonomis pembungkit termal dengan bahasa C menggunakan sortware visual C++ 6