An improved semiempirical method for power-on base drag prediction

2001 ◽  
Author(s):  
F. Moore ◽  
T. Hymer
Keyword(s):  
Semiempirical Method ◽  
Drag Prediction ◽  
Base Drag

Base drag prediction on missile configurations

1994 ◽  
Vol 31 (5) ◽  
pp. 759-765 ◽  
Author(s):  
F. G. Moore ◽  
F. Wilcox ◽  
T. Hymer
Keyword(s):  
Drag Prediction ◽  
Base Drag

Study of Base DRAG Prediction With Chamber Pressure at Super-Sonic Flow

2020 ◽  
Vol 48 (11) ◽  
pp. 849-859
Author(s):  
Duk-Min Kim ◽  
Junyeop Nam ◽  
Hyoung Jin Lee ◽  
Kyung-Ho Noh ◽  
Daeyeon Lee ◽  
...  
Keyword(s):  
Chamber Pressure ◽  
Sonic Flow ◽  
Drag Prediction ◽  
Base Drag

scholarly journals IMPLEMENTATION OF SEMI-EMPIRICAL MODELS TO ENHANCE THE ACCURACY OF PANEL METHODS FOR DRAG PREDICTION AT SUPERSONIC SPEEDS

2011 ◽  
Vol 12 (3) ◽  
Author(s):  
Abdulkareem Shafiq Mahdi Al-Obaidi
Keyword(s):  
Computer Program ◽  
Panel Method ◽  
Preliminary Design ◽  
Empirical Methods ◽  
Average Value ◽  
Panel Methods ◽  
Drag Prediction ◽  
Stall Angle ◽  
Semi Empirical ◽  
Base Drag

This paper introduces an attempt to enhance the accuracy of panel methods. A low-order panel method is selected and coupled with semi-empirical methods to enhance the accuracy of drag prediction of flying bodies at supersonic speeds. The semi-empirical methods are used to improve the accuracy of drag prediction by mathematical modelling of viscosity, base drag, and drag due to wing-body interference. Both methods were implemented by a computer program and validated against experimental and analytical results. The comparisons show that a considerable improvement has been achieved for the selected panel method for prediction of drag coefficients. In general, accuracy within an average value of -4.4% was obtained for the enhanced panel method. Such accuracy could be considered acceptable for the preliminary design stages of supersonic flying bodies such as projectiles and missiles. The developed computer program gives satisfactory results as long as the considered configurations are slender and the angles of attack are small (below stall angle).  ABSTRAK: Kertas kerja ini memperkenalkan percubaan untuk  mempertingkatkan ketepatan kaedah panel. Kaedah panel tertib rendah telah dipilih dan digabungkan dengan kaedah separa empirik untuk mempertingkatkan ketepatan ramalan seret objek terbang pada kelajuan supersonik. Kaedah semi empirikal yang digunakan untuk meningkatkan ketepatan jangkaan seret menggunakan model matematik bagi kelikatan, seretan dasar, dan  seretan disebabkan  oleh badan sayap interferens. Kedua-dua kaedah dijalankan menggunakan program komputer dan disah berdasarkan keputusan uji kaji dan analisis. Perbandingan keputusan menunjukkan peningkatan yang mendadak diperolehi melalui kaedah panel yang telah dipilih sebagai jangkaan pekali seret. Secara umumnya, ketepatan yang melingkungi nilai purata sebanyak -4.4% telah diperolehi daripada kaedah peningkatan panel. Keputusan sebegini boleh diterima untuk peringkat reka bentuk permulaan bagi objek terbang supersonik seperti projektil dan misil. Program komputer yang direka memberikan keputusan yang memuaskan selagi konfigurasi yang dipilih adalah kecil dan sudut serangan adalah rendah (di bawah sudut tegun).

Base drag prediction on missile configurations

1993 ◽  
Author(s):  
F. MOORE ◽  
T. HYMER ◽  
F. WILCOX
Keyword(s):  
Drag Prediction ◽  
Base Drag

Plume-On Base Drag Prediction Including Three-Dimensional and Real-Gas Effects

2001 ◽  
Vol 38 (2) ◽  
pp. 136-142 ◽  
Author(s):  
G. Rubio ◽  
A. Matesanz ◽  
A. Velazquez
Keyword(s):  
Three Dimensional ◽  
Real Gas ◽  
Real Gas Effects ◽  
Drag Prediction ◽  
Base Drag

Data Summary from First AIAA Computational Fluid Dynamics Drag Prediction Workshop

2003 ◽  
Vol 40 (5) ◽  
Author(s):  
David W. Levy ◽  
Tom Zickuhr ◽  
John Vassberg ◽  
Shreekant Agrawal ◽  
Richard A. Wahls ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Prediction

Influence of solvent polarity on the dual fluorescence of p-N,N-dimethylaminobenzonitrile: An AM1 theoretical study

1990 ◽  
Vol 55 (8) ◽  
pp. 1891-1895 ◽  
Author(s):  
Peter Ertl
Keyword(s):  
Excited State ◽  
Theoretical Study ◽  
Solvent Polarity ◽  
Semiempirical Method ◽  
Dual Fluorescence ◽  
Long Wavelength ◽  
Polar Media ◽  
Wavelength Emission ◽  
Ground State Geometry ◽  
Influence Of Solvent

Twisting of the NMe2 group in p-N,N-dimethylaminobenzonitrile (DMABN) was investigated using AM1 semiempirical method with configuration interaction. Effect of polar media was considered by placing + and - charge centers ("sparkles") at appropriate places opposite the molecule. Optimized ground state geometry of DMABN is slightly twisted with the lowest vertical excited state of 1B character. As the polarity of media increases and/or the - NMe2 group twists, the symmetric 1A excited state having considerable charge separation becomes energetically favorable. Anomalous long-wavelength emission of DMABN comes from this state.

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