The Voith Schneider® Propeller Current Applications and New Developments

Voith Turbo The Voith Schneider® Propeller Current Applications and New Developments Dr.-Ing. Jens-Erk Bartels, Dr.-Ing. Dirk Jürgens 1.Introduction 1. Introduction Voith Schneider® propellers (VSP) VSPs are currently used primarily Combined with the use of modern The Voith Schneider® propeller is 2. Construction of the Voith are used primarily for ships that on tugs, double-ended ferries (DEF), development tools (3D-CAD, FEM), based on an invention by Ernst Schneider® Propeller have to satisfy particularly demand- mine countermeasure vessels CFD is opening up new prospects Schneider dating from 1925. The 3. The hydrodynamic principle of ing safety and maneuverability (MCMV), passenger ships, buoy for accelerated development work. Voith company took up the idea thrust generation requirements. The special charac- layers and floating cranes. The de- Continuous improvements in its and, working with the inventor, 4. Hydrodynamic characteristics of teristic of the Voith Schneider® pro- velopment of the Voith Water Trac- hydromechanical properties will brought it to maturity. By 1927, the Voith Schneider® Propellers peller is its vertical axis of rotation. tor (VWT) is a highlight. The VWT bring in new applications for this propeller was sufficiently advanced 5. Hydrodynamic calculation The thrust is generated by sepa- has significantly increased the saf- type of propeller. The Voith Cy- for a test boat to be ordered. The methods for Voith Schneider® rately oscillating, balanced propeller ety of tug operations. When escort- cloidal Rudder (VCR) is an exten- idea behind the Voith Water Tractor propellers blades. Due to its physical operat- ing ships carrying hazardous cargo, sion of the VSP technology. It is a and its practical implementation are 6. Ships with Voith Schneider® ing principle and its design, thrust the Voith Water Tractor achieves dual mode propulsor and rudder associated with Voith engineer propellers adjustments can be made very high assistance forces for a with two operating modes: active Wolfgang Baer. Development of the 7. The Voith Cycloidal Rudder extremely rapidly. The VSP is a wide speed range thanks to its and passive. In its passive mode, VWT started in 1952. (VCR) controllable-pitch propeller that optimum design. It enables escort the VCR operates as a conven- The following sections describe the 8. Bibliography permits continuously variable thrust duties to be carried out safely, even tional rudder; in the active mode it construction of the Voith Schneider® adjustment through 360°. The VSP at high speeds. The Voith Water operates similar to the well-proven propeller, the physical principle combines steering and propulsion. Tractor marked the introduction of Voith Schneider® propeller. This behind its operation and examples Its rapid, step-less thrust variation the indirect steering to ship assis- new multi-functional system im- of its application. They also de- according to X/Y coordinates, in tance. The Voith Turbo Fin (VTF) is proves the maneuverability of ships scribe recent developments such particular, improves ship handling. a new development that permits equipped with conventional screw as the Voith Cycloidal Rudder and Voith Schneider® propellers operate further improvements in the escort propellers as their main propulsion the Voith Turbo Fin. at comparatively low number of capabilities of Voith Water Tractors. system and in particularly enhances revolutions and are therefore no- Recently, the systematic use of their safety, since it can be de- table for their long service life and computational fluid dynamic (CFD) signed as a redundant propulsion very low maintenance require- has provided a more detailed un- system. ments. derstanding of the flow physics of the Voith Schneider® propeller. 1 2 Construction of the Voith Schneider® propeller Figure 1: Voith Schneider® propeller incorporated into a ship’shull Figure 2: General comparison between Voith Figure 3: VSP Type GII, (3D CAD drawing) Figure 4: Sectioned view of Type-GII Figure 5: Kinematic principle of the Schneider® propeller and screw propeller Voith Schneider® propeller Voith Schneider® propeller The Voith Schneider® propeller A significant difference between the axially supported by the thrust plate speed of rotation without creating robust crank-type kinematic system. the eccentricity can be varied very generates thrust by means of pro- Voith Schneider® propeller and the (10) and centered radial by the transverse forces. Figure 5 illustrates the kinematic quickly and with little power from filed blades which project from the screw propeller is the direction of roller bearing (11).Due to the kine- The division into propulsion thrust principle of the VSP. the servo motors, thanks to the bottom of the ship and rotate about the axis of rotation relative to the matic system (3), the blades (2) and steering forces, i.e. steering If the centre of the lower spherical considerable leverage effect of the a global vertical axis. The blades direction of thrust. Whereas in the perform an oscillating motion. The according to Cartesian coordinates, bearing (steering centre) is at the control rod (see Figure 5). This are mounted in a rotor casing, case of screw propellers the axis of amplitude and phase of the blades' makes handling the ship an easily centre of the rotor casing, the technical solution is the basis for which ends flush with the bottom of rotation and the direction of thrust motion is determined by the posi- understood and user-friendly blades are not angled relative to the rapid and sensitive variation the ship (Figure 1). are nearly identical, with the VSP tion of the steering centre and process for the helmsman. Fitting the tangent to the blade circle in thrust of Voith Schneider® Superimposed on the global rotary they are perpendicular to one hence the magnitude and direction the Voith Schneider® propeller with (Figure 6a). If the lower spherical propellers. For reasons of design, motion of the blades about the another (Figure 2). of thrust are varied by means of the mechanical controls for the servo bearing is moved away from the the mechanical eccentricity, i.e. the common vertical axis is a local control rod (4). motors and an oil pump (12) centre of the rotor casing by the position of the lower spherical oscillating motion about the respec- With the Voith Schneider® propeller, The control rod is actuated by two flanged to the input gear results in actuation of one or both servo bearing (Figure 5) is very much tive axis of each blade's shaft. To therefore, there is no preferential orthogonal arranged servo motors a self-contained propulsion and motors and the lever action of the less than that of the position of the generate the oscillating motion, a direction of thrust. The VSP is a (5).