Performance Of Ducted Propeller Research Articles

Numerical investigation on the performance of ducted propeller

As a part of the important thing in ship design is propeller design. Propeller its self has many kinds of the design. This study investigates the effect on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the Computational Fluid Dynamics (CFD) method. These simulations were compared in accordance SHUSKIN nozzle that has 3 types of design. Each type of thruster model indicates different force and torque. Thus, for the analysis will be generated by each model and it can be discovered that which model has the most optimal for the thrust. The analysis by using CFD indicates the change of fluid flow around the ducted propeller. The results showed that the nozzle on the propeller will give the extra of thrust for the performance of propeller.

Numerical investigation of tip clearance effects on the performance of ducted propeller

Tip clearance loss is a limitation of the improvement of turbomachine performance. Previous studies show the Tip clearance loss is generated by the leakage flow through the tip clearance, and is roughly linearly proportional to the gap size. This study investigates the tip clearance effects on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the commercial Computational Fluid Dynamic (CFD) code CFX14.5. These simulations were carried out to determine the underlying mechanisms of the tip clearance effects. The calculations were performed at three different chosen advance ratios. Simulation results showed that the tip loss slope was not linearly at high advance due to the reversed pressure at the leading edge. Three type of vortical structures were observed in the tip clearance at different clearance size.

The Research of Hydrodynamic Performance for Ducted Propeller with PBCF

The Propeller Boss Cap Fins (PBCF) is often used to ordinary propeller, a good energy-saving effect being obtained. In order to study the energy-saving mechanism of ducted propeller with PBCF, in this paper, the FLUENT has been taken to simulate the distribution of thrust coefficient, torque coefficient, blade pressure and velocity vector of hub surface at different advance coefficients. By contrasting the results of numerical simulation of hydrodynamic performance of ducted propeller between with fins and without fins, we know that at the low advance coefficient, the ducted propeller with fins will increase the thrust coefficient and decrease the torque coefficient; rising the open water propeller efficiency, improving the efficiency under the premise of the efficiency increase by duct. The existence of fins has changed velocity distribution of water around the hub and made the water that flowed around the propeller hub with propeller rotation direction flow to propeller tail along the fins not gather in the cub, so it weakened the hub vortex.

Influence of Finite Tip Clearance on the Tip Flow Characteristics of Ducted Propeller

The influence of finite tip clearances on the tip flow characteristics, as well as pressure distribution on blade surface near the tip and open water performance of ducted propeller 19A/Ka4-55 model is studied in this paper. It is discovered that tip leakage vortex (TLV for short) disappears when clearance size reduces to a certain extent (0.08% of the propeller radius in this model). The decreasing of tip clearance size also leads to increasing efficiency and better cavitation performance. Besides, variation of thrust and torque coefficient with clearance size show stepped shape instead of linear.

Unsteady Hydrodynamic Performance Prediction of Ducted Propeller Based on CFD

Firstly, the calculated model was created in UG and GAMBIT, and then the Moving Mesh method was adopted to simulate thrust and torque of ducted propeller using FLUENT in the open water. The thrust, torque and bearing force of ducted propeller in three different wake fields were calculated. And the influence on the performance of ducted propeller by the wake fields was analyzed.

Influence Analysis of Blade Fracture on Hydrodynamic Performance of Ducted Propellers Based on CFD

The numerical model of the unsteady flow field of ducted propellers is based on CFD (computational fluid dynamics). By applying the numerical model, the unsteady hydrodynamic performance of the ducted propeller with the fracture at different positions of a certain blade is numerically analyzed under three different wake current fields. Based on regress analysis ,the relationships between the mean KQ、mean KT and the quantity of the blade fracture of ducted propellers are obtained; and the relationships between hydrodynamic coefficients Kp, KQ, KFy (Bearing force coefficient of the propeller) and wake current fields , the quantity of the blade fracture are respectively further analyzed. The results show that: (1) with the increase of the quantity of the blade fracture, the amplitude of bearing force periodic variation of propellers increases, while the thrust and torque reduce; (2) the bearing force of propellers is similarly sine-varying, and the frequency of its variation is unrelated to the normal variation frequency of the wake current field. The more non-uniform the wake current field is, the more the amplitude of its periodic variation is; (3) the thrust and torque of propeller are similarly sine-varying, and the frequencies of their variation are related to the normal variation frequency of the wake current field. And the frequencies equal the shaft frequency multiplied the normal variation frequency of the wake current field. The more non-uniform the wake current field is, the more the amplitude of their periodic variation is.

Using the surface panel method to predict the steady performance of ducted propellers

A new numerical method was developed for predicting the steady hydrodynamic performance of ducted propellers. A potential based surface panel method was applied both to the duct and the propeller, and the interaction between them was solved by an induced velocity potential iterative method. Compared with the induced velocity iterative method, the method presented can save programming and calculating time. Numerical results for a JD simplified ducted propeller series showed that the method presented is effective for predicting the steady hydrodynamic performance of ducted propellers.