Diagnostic-Photographic Determination of Drag/Lift/Torque Coefficients of a High Speed Rigid Body in a Water Column

2009 ◽  
Vol 77 (1) ◽  
Author(s):  
Peter C. Chu ◽  
Chenwu Fan ◽  
Paul R. Gefken
Keyword(s):  
Rigid Body ◽  
Water Column ◽  
Fast Moving ◽  
High Speed ◽  
Test Site ◽  
Empirical Method ◽  
Empirical Formulas ◽  
The Cost ◽  
Semi Empirical

Prediction of a rigid body falling through water column with a high speed (such as Mk-84 bomb) needs formulas for drag/lift and torque coefficients, which depend on various physical processes such as free surface penetration and bubbles. A semi-empirical method is developed in this study to determine the drag/lift and torque coefficients for a fast-moving rigid body in a water column. The theoretical part is to derive the relationships (called diagnostic relationships) between (drag, lift, and torque) coefficients and (position and orientation) of the rigid body from the three momentum equations and the three moment of momentum equations. The empirical part is to collect data of trajectory and orientation of a fast-moving rigid body using multiple high-speed video cameras (10,000 Hz). Substitution of the digital photographic data into the theoretical relationships leads to semi-empirical formulas of drag/lift and torque coefficients, which are functions of the Reynolds number, attack angle, and rotation rate. This method was verified by 1/12th Mk-84 bomb strike experiment with various tail configurations (tail section with four fins, two fins, and no fin and no-tail section) conducted at the SRI test site. The cost of this method is much lower than the traditional method using the wind tunnel. Various trajectory patterns are found for different tail configurations.

Study on Two-Phase Fuel Distributions in High-Speed Hot Transverse Air Stream

1986 ◽  
Vol 108 (3) ◽  
pp. 485-490
Author(s):  
Mao-lin Yang ◽  
Shan-jian Gu ◽  
Xiang-yi Li
Keyword(s):  
High Speed ◽  
Empirical Method ◽  
Mass Center ◽  
Two Phase ◽  
Fuel Distribution ◽  
Hot Air ◽  
Air Stream ◽  
Cold Stream ◽  
Fuel Evaporation ◽  
Semi Empirical

It was found that fuel distribution in a hot high-speed transverse air stream differed greatly from that in a cold stream. In a hot air stream there exist two-phase fuel distributions, and hence, two mass center lines extending downstream. Experimental results of fuel distributions are presented. By using the model of trajectory with diffusion and also considering the fuel evaporation, a semi-empirical method to predict two-phase fuel distributions has been developed.

scholarly journals Determination of plasma temperature by a semi-empirical method

2004 ◽  
Vol 34 (4b) ◽  
pp. 1673-1676 ◽  
Author(s):  
F. O. Borges ◽  
G. H. Cavalcanti ◽  
A. G. Trigueiros
Keyword(s):  
Plasma Temperature ◽  
Empirical Method ◽  
Semi Empirical

scholarly journals THE SYNTHESIS OF 1,3-DIMETHYL-6,7-DIMETHOXY-3,4-DIHYDROISOQUINOLINE FROM METHYLEUGENOL : APPLICATION OF RITTER REACTION FOR DIRECTLY CYCLIZATION

2010 ◽  
Vol 6 (3) ◽  
pp. 286-291 ◽  
Author(s):  
M. Farid Rahman ◽  
Elvina Dhiaul Iftitah
Keyword(s):  
Sulphuric Acid ◽  
Room Temperature ◽  
Acid Catalyst ◽  
Empirical Method ◽  
Low Energy ◽  
Ritter Reaction ◽  
Experimental Laboratory ◽  
Semi Empirical

The synthesis of 1,3-dimethyl-6,7-dimethoxy-3,4-dihydroisoquinoline from methyleugenol with application of Ritter reaction for directly cyclization was presented. This research was carried out in 2 steps : (1) Determination of intermediate stability that undergo in the reaction by using hyperchem version 6 with AM 1 semi empirical method, and (2) Synthesis of dihydroisoquinoline from methyleugenol and acetonitrile with acid catalyst (H2SO4) in the laboratory. The result of AM 1 calculation found that generally, the intermediate encourage the formation dihydroisoquinoline product, had low energy were compared with the intermediate in other product. Therefore, the dihydroisoquinoline product was easily formed. The result of experimental laboratory found that dihydroisoquinoline could be synthesed from methyleugenol and acetonitrile in the presence sulphuric acid under reflux in 74,92% yields. In despite, the minor product was formed with amount 6,74%. While the reaction at room temperature gave dihydroisoquinoline in poor yield about 11,42%.   Keywords: stability of intermediate, dihydroisoquinoline, Ritter reaction

scholarly journals Study on Two-Phase Fuel Distributions in High Speed Hot Transverse Air Stream

1985 ◽  
Author(s):  
Yang Mao-Lin ◽  
Gu Shan-Jian ◽  
Li Xiang-Yi
Keyword(s):  
High Speed ◽  
Empirical Method ◽  
Mass Center ◽  
Two Phase ◽  
Fuel Distribution ◽  
Hot Air ◽  
Air Stream ◽  
Cold Stream ◽  
Fuel Evaporation ◽  
Semi Empirical

It was found that fuel distribution in a hot high speed transverse air stream differed greatly from that in a cold stream. In a hot air stream there exist two-phase fuel distributions, hence, two mass center lines extending downstream. Experimental results of fuel distributions are presented. By using the model of trajectory with diffusion and also considering the fuel evaporation, a semi-empirical method to predict two-phase fuel distributions has been developed.

A decision support method for internal truck employment

2014 ◽  
Vol 114 (9) ◽  
pp. 1378-1395 ◽  
Author(s):  
Z.X. Wang ◽  
Felix T.S. Chan ◽  
S.H. Chung ◽  
Ben Niu
Keyword(s):  
Cost Effective ◽  
Empirical Method ◽  
Container Terminals ◽  
Storage Allocation ◽  
Content Type ◽  
Truck Scheduling ◽  
Integration Problem ◽  
The Cost

Purpose – The purpose of this paper is to propose a model that determines the strategy of owning and renting trucks in combinations with internal truck scheduling and storage allocation problems in container terminals. Design/methodology/approach – To deal with this complicated problem, a two-level heuristic approach is developed, in which the integration problem is decomposed into two levels. The first level determines the daily operations of the internal trucks, while the second level determines the truck employment strategy based on the calculation in the first level. Findings – The results show that: even if the using cost of owned yard trucks is much lower than the cost of rented yard tucks, terminal companies should not purchase too many trucks when the purchasing price is high. In addition, the empirical truck employment strategies, which are purchasing all the trucks or renting all the trucks, are not cost-effective when compared with the proposed yard truck employment strategy. Originality/value – The paper provides a novel insight for the internal truck employment strategy in container terminals which is the determination of the strategy of employing renting and outsourcing yard trucks to meet operational daily transportation requirements and minimize the long-term cost of employing yard trucks. A mathematical model is proposed to deal with the practical problem. Also, this study presents better solution than empirical method for employing different types of yard truck. Thus, in order to obtain more benefit, terminal companies should employ the proposed yard truck employment strategy.

Identification of Load Applying on T-Shape Joint with Inverse Problem

2006 ◽  
Vol 326-328 ◽  
pp. 657-660
Author(s):  
Joon Hyuk Song ◽  
Hee Yong Kang ◽  
Hyo Sun Yu ◽  
Sung Mo Yang
Keyword(s):  
Principal Stress ◽  
Empirical Method ◽  
Data Sets ◽  
Strain Gages ◽  
Unit Load ◽  
Principal Stresses ◽  
Driving Condition ◽  
In The Beginning ◽  
The Cost

In the beginning of design, exact load data are actually necessary for the fatigue strength and life analysis to minimize the cost and time of designing. The procedure of practical load determination is developed by the combination of the principal stresses of F.E.Analysis and experiment. This paper conceives new procedure for the determination of load direction and magnitude applied on mechanical structures. New procedure is the combination of the analytical and empirical method with analyzed strain by F.E. Analysis under unit load and with measured principal stress by strain gages under driving load, respectively. In this paper, we theorize the procedure of practical load determination and make the validity and the practicality of the procedure with the application to T-shape jointed structure. F.E. Analysis is conducted to get the principal stress on arbitrary points in the F.E. model of T-shape joint under unit load. Then experiment is carried out to get the principal stress on the same points of F.E. model. To demonstrate the actual driving condition, the load conditions are bending and torsion. From these two data sets, the magnitude, the direction and the position of load can be obtained.

Sign in / Sign up

Export Citation Format

Share Document