| Counterrotating Propulsive System |
DEC 1981 |
|
| Authors:
S. Taskonas; W. R. Jacobs; P. Liao; STEVENS INST OF TECH HOBOKEN NJ DAVIDSON LAB
|
 | Linearized unsteady lifting surface theory has been applied in the study of counterrotating propeller systems with equal or unequal number of blades operating in uniform or nonuniform inflow fields when both units are rotating with the same RPM. The mathematical model takes into account as realistically as possible the geometry of the propulsive device, the mutual interaction of both units and the three-dimensional spatially varying inflow field. The propeller blades ... |
|
| The Linearized Unsteady Lifting Surface Theory Applied to the Pump-Jet Propulsive System |
AUG 1981 |
|
| Authors:
W. R. Jacobs; S. Tsakonas; Ping Liao; STEVENS INST OF TECH HOBOKEN NJ DAVIDSON LAB
|
| A theoretical analysis is developed treating the 'Pump-Jet' propulsive unit comprised of stator, rotor and enshrouding nozzle by using the unsteady lifting surface theory. The analysis takes into account accurate geometry, realistic flow conditions and hydrodynamic interactions between all lifting surfaces of finite thickness distribution. The system is assumed to be immersed in a non-uniform flow of an incompressible fluid. Expressions have been developed for loadings on all interacting surfaces ... |
|
| Blade Pressure Distribution for a Moderately Loaded Propeller. |
SEP 1980 |
|
| Authors:
S. Tsakonas; John P. Breslin; W. R. Jacobs; STEVENS INST OF TECH HOBOKEN NJ DAVIDSON LAB
|
| A new theoretical procedure has been developed modifying the existing analysis for a marine propeller operating in a nonuniform inflow field by considering the radially varying mean wake and mean propeller induction. In addition, the selection of a new reference surface around which the perturbation analysis is developed is based on the nonlinear form of the Bernoulli equation together with an appropriate kinematic condition existing at the propeller operational condition. ... |
|
| Propeller Blade Pressure Distribution due to Loading and Thickness Effects. |
APR 1976 |
93 pages |
| Authors:
S. Tsakonas; W. R. Jacobs; M. R. Ali; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
 | A theoretical approach is developed and a computational procedure adaptable to a high speed digital computer is established for the evaluation of the blade pressure distribution of a marine propeller due to thickness and loading effects. The dual role of the blade thickness is considered. The contribution of the nonplanar thickness to the propeller loading and pressure distribution and the effect of the flow distortion thickness are studied by means ... |
|
| Propeller-Duct Interaction Due to Loading and Thickness Effects. |
APR 1975 |
|
| Authors:
S. Tsakonas; W. R. Jacobs; M. R. Ali; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
| This study is a continuation of an earlier investigation dealing with the interaction of a propeller and its enshrouding nozzle when both are operating in a nonuniform inflow field. The present investigation complements the previous one by introducing thickness of both lifting surfaces and camber of the duct. Thus a complete analysis is available which takes into account the true geometry of the propeller and duct, including the propeller and ... |
|
| Lifting Surface Theory and Hydroelastic Instability. |
SEP 1973 |
|
| Authors:
S. Tsakonas; W. R. Jacobs; M. R. Ali; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
| A brief review is presented of the unsteady lifting surface theory and of the 'generalized lift operator' technique of inverting the 'downwash' integral equation. The integral equation approach is then employed to predice responses of various foils to pitching oscillations and to forward motion in a regular wave train. The agreement between theoretical predictions and experimental results is good for simple configurations without appendages, but not in the case of ... |
|
| Propeller-Induced Velocity Field due to Thickness and Loading Effects. |
JUL 1973 |
|
| Authors:
W. R. Jacobs; S. Tsakonas; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
| Blade thickness palys a dual role, contributing to the lifting characteristics of the blade because of its nonplanar form as well as to its non-lifting characteristics due to the generation of a symmetrical flow disturbance. However, since the so-called 'nonplanar thickness' has been shown to have little effect on the flade pressure distribution and thus presumably to have a negligible effect on the velocity and pressure field around an operating ... |
|
| Propeller-Rudder Interaction Due to Loading and Thickness Effects. |
SEP 1972 |
|
| Authors:
S. Tsakonas; W. R. Jacobs; M. R. Ali; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
| The previous analysis of the propeller-rudder interaction problem by means of the lifting surface theory has been modified to include the effects of thickness of both surfaces. The effect of thickness on the 'flow displacement' in the field is taken into account by the 'thin body' approach. The blade thickness effect on the loading of the propeller blade due to its non-planar form, being small, is neglected. The resulting field ... |
|
| Theory and Measurements of the Propeller-Induced Vibratory Field. |
DEC 1970 |
|
| Authors:
W. R. Jacobs; J. Mercier; S. Tsakonas; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
| A theory has been developed, based on lifting surface theory, for evaluation of the pressure field generated by an operating propeller in a non-uniform inflow field. In addition, an experimental procedure and a signal processing technique for measuring small pressure levels accurately have been established and utilized in an extensive experimental program. Theoretical results obtained by means of a computer program developed for the CDC 6600 high-speed digital computer agree ... |
|
| A THEORY FOR THE PROPELLER-RUDDER INTERACTION. |
AUG 1968 |
|
| Authors:
S. Tsakonas; W. R. Jacobs; M. R. Ali; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
| The propeller-rudder interaction problem is studied by means of the unsteady lifting-surface theory. Both surfaces of arbitrary geometry are immersed in a nonuniform flowfield (i.e., hull wake) of an ideal incompressible fluid. The boundary-value problem yields a pair of surface integral equations, the inversion of which is achieved by the so-called 'generalized lift operator' technique, a new approach developed by the authors, in conjunction with the presently used 'mode-collocation' method. ... |
|
| UNSTEADY PROPELLER LIFTING-SURFACE THEORY WITH FINITE NUMBER OF CHORDWISE MODES, |
DEC 1966 |
|
| Authors:
S. Tsakonas; W. R. Jacobs; P. H. Rank Jr; STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB
|
| A continuing investigation is concerned with improvement of the mathematical model developed for the evaluation of the steady and time-dependent loading distributions on the blades of marine propellers operating in spatially non-uniform flow. The surface integral equation resulting from the theory was solved by means of the collocation method, in conjunction with the generalized lift operator, for a prescribed set of chordwise modes which reproduce the proper leading-edge singularity and ... |
|
Reports by Author
