Select your configuration

Wind Propulsion System (WAPS)

CL_max : 0

CL_max

Represent the maximum force per unit area that the system can develop.

For similar aerodynamic characteristics, a higher Cl max allows reducing the surface area of the system.

For a wide range of apparent wind angles, this is the operating point of the aerodynamic polar curve that maximizes the propulsive force, and therefore energy savings.

Area [m²] : 0

Area

The aerodynamic area of a WAPS is the planform area or projected area of the system.

It is the product of the span (the height) by the chord (the width).

Aerodynamic forces are basically proportional to the area for a single device of a similar aspect ratio.

Span [m] : 0

Span

Span define the extension of a wing. For WAPS it is the height of the device.

For a given area, changing the span will influence the aspect ratio of the wing.

A larger aspect ratio will increase the aerodynamic efficiency of the wing but it is usually constrained by mechanical aspects.

Number of devices: 0

Number of devices

One of the easiest mean to increase the area of the WAPS on board is to use multiples devices. This is also a way to limit the air draft of the ship fitted with a WAPS.

However, multiple devices interact strongly with each other, in any conditions, inducing a loss of efficiency compared to a single device in isolation.

Interaction effects between the devices depend on the number of devices, the relative position of the devices, the apparent wind angle and much more.

CRAIN has developed tools in order to assess these kind of interactions.

CL_max : 0

CL_max

Represent the maximum force per unit area that the system can develop.

For similar aerodynamic characteristics, a higher Cl max allows reducing the surface area of the system.

For a wide range of apparent wind angles, this is the operating point of the aerodynamic polar curve that maximizes the propulsive force, and therefore energy savings.

Area [m²] : 0

Area

The aerodynamic area of a WAPS is the planform area or projected area of the system.

It is the product of the span (the height) by the chord (the width).

Aerodynamic forces are basically proportional to the area for a single device of a similar aspect ratio.

Span [m] : 0

Span

Span define the extension of a wing. For WAPS it is the height of the device.

For a given area, changing the span will influence the aspect ratio of the wing.

A larger aspect ratio will increase the aerodynamic efficiency of the wing but it is usually constrained by mechanical aspects.

Number of devices:0

Number of devices

One of the easiest mean to increase the area of the WAPS on board is to use multiples devices. This is also a way to limit the air draft of the ship fitted with a WAPS.

However, multiple devices interact strongly with each other, in any conditions, inducing a loss of efficiency compared to a single device in isolation.

Interaction effects between the devices depend on the number of devices, the relative position of the devices, the apparent wind angle and much more.

CRAIN has developed tools in order to assess these kind of interactions.

CL_max : 0

CL_max

Represent the maximum force per unit area that the system can develop.

For similar aerodynamic characteristics, a higher Cl max allows reducing the surface area of the system.

For a wide range of apparent wind angles, this is the operating point of the aerodynamic polar curve that maximizes the propulsive force, and therefore energy savings.

Area [m²] : 0

Area

The aerodynamic area of a WAPS is the planform area or projected area of the system.

It is the product of the span (the height) by the chord (the width).

Aerodynamic forces are basically proportional to the area for a single device of a similar aspect ratio.

Span [m] : 0

Span

Span define the extension of a wing. For WAPS it is the height of the device.

For a given area, changing the span will influence the aspect ratio of the wing.

A larger aspect ratio will increase the aerodynamic efficiency of the wing but it is usually constrained by mechanical aspects.

Number of devices:0

Number of devices

One of the easiest mean to increase the area of the WAPS on board is to use multiples devices. This is also a way to limit the air draft of the ship fitted with a WAPS.

However, multiple devices interact strongly with each other, in any conditions, inducing a loss of efficiency compared to a single device in isolation.

Interaction effects between the devices depend on the number of devices, the relative position of the devices, the apparent wind angle and much more.

CRAIN has developed tools in order to assess these kind of interactions.

CL_max : 0

CL_max

Represent the maximum force per unit area that the system can develop.

For similar aerodynamic characteristics, a higher Cl max allows reducing the surface area of the system.

For a wide range of apparent wind angles, this is the operating point of the aerodynamic polar curve that maximizes the propulsive force, and therefore energy savings.

Area [m²] : 0

Area

The aerodynamic area of a WAPS is the planform area or projected area of the system.

It is the product of the span (the height) by the chord (the width).

Aerodynamic forces are basically proportional to the area for a single device of a similar aspect ratio.

Span [m] : 0

Span

Span define the extension of a wing. For WAPS it is the height of the device.

For a given area, changing the span will influence the aspect ratio of the wing.

A larger aspect ratio will increase the aerodynamic efficiency of the wing but it is usually constrained by mechanical aspects.

Number of devices:0

Number of devices

One of the easiest mean to increase the area of the WAPS on board is to use multiples devices. This is also a way to limit the air draft of the ship fitted with a WAPS.

However, multiple devices interact strongly with each other, in any conditions, inducing a loss of efficiency compared to a single device in isolation.

Interaction effects between the devices depend on the number of devices, the relative position of the devices, the apparent wind angle and much more.

CRAIN has developed tools in order to assess these kind of interactions.

CL_max : 0

C_Lmax

Represent the maximum force per unit area that the system can develop. In case of the rotor, this is the maximum operating lift coefficient taken into account. Rotor could achieve a higher lift coefficient but at the cost of a much higher energy consumption.

For similar aerodynamic characteristics, a higher Cl max allows reducing the surface area of the system.

For a wide range of apparent wind angles, this is the operating point of the aerodynamic polar curve that maximizes the propulsive force, and therefore energy savings.

Diameter [m] : 0

Diameter

Multiplied by the span, the diameter affects the surface. The latter is proportionnal to the aerodynamic forces.

For a given area, or a given span, changing the diameter will influence the aspect ratio of the Rotor.

A larger aspect ratio will increase the aerodynamic efficiency of the Rotor but it is usually constrained by mechanical aspects.

Span [m] : 0

Span

Span define the extension of a wing. For WAPS it is the height of the device.

For a given area, changing the span will influence the aspect ratio of the wing.

A larger aspect ratio will increase the aerodynamic efficiency of the wing but it is usually constrained by mechanical aspects.

Number of devices:0

Number of devices

One of the easiest mean to increase the area of the WAPS on board is to use multiples devices. This is also a way to limit the air draft of the ship fitted with a WAPS.

However, multiple devices interact strongly with each other, in any conditions, inducing a loss of efficiency compared to a single device in isolation.

Interaction effects between the devices depend on the number of devices, the relative position of the devices, the apparent wind angle and much more.

CRAIN has developed tools in order to assess these kind of interactions.

CL_max : 0

CL_max

Represent the maximum force per unit area that the system can develop.

For similar aerodynamic characteristics, a higher Cl max allows reducing the surface area of the system.

For a wide range of apparent wind angles, this is the operating point of the aerodynamic polar curve that maximizes the propulsive force, and therefore energy savings.

Area [m²] : 0

Area

The aerodynamic area of a WAPS is the planform area or projected area of the system.

It is the product of the span (the height) by the chord (the width).

Aerodynamic forces are basically proportional to the area for a single device of a similar aspect ratio.

Span [m] : 0

Span

Span define the extension of a wing. For WAPS it is the height of the device.

For a given area, changing the span will influence the aspect ratio of the wing.

A larger aspect ratio will increase the aerodynamic efficiency of the wing but it is usually constrained by mechanical aspects.

Number of devices:0

Number of devices

One of the easiest mean to increase the area of the WAPS on board is to use multiples devices. This is also a way to limit the air draft of the ship fitted with a WAPS.

However, multiple devices interact strongly with each other, in any conditions, inducing a loss of efficiency compared to a single device in isolation.

Interaction effects between the devices depend on the number of devices, the relative position of the devices, the apparent wind angle and much more.

CRAIN has developed tools in order to assess these kind of interactions.

Operating CL : 0

Operating CL

Translates into the operating force per unit area that the system can develop.

For similar aerodynamic characteristics, a higher operationnal CL means a smaller surface area.

For the vast majority of apparent wind angles at which the propulsion system operates, this is the point on the aerodynamic polar curve that maximizes propulsive force, and therefore energy savings.

Lift to drag ratio : 0

Lift to drag ratio

The relationship between a system's lift and drag.

For all systems, high lift is often at the expense of higher drag.

A high ratio is therefore synonymous with high performance.

Area [m²] : 0

Area

The aerodynamic area of a WAPS is the planform area or projected area of the system.

It is the product of the span (the height) by the chord (the width).

Aerodynamic forces are basically proportional to the area for a single device of a similar aspect ratio.

Elevation [deg] : 0

Elevation

Angle between the horizontal and the mean position of the kite line.

This parameter is particularly important for performance, but also from a technical point of view.

Route

The energy production of the WAPS depends hugely on wind speed and direction.

In order to assess the average energy production on the operating routes of the ship, the energy production need to be combined with the wind statistics on the route.

SimWAPS propose various samples of routes for which we have derived the wind statistics (using ECMWF – ERA5).

No weather routing, which may increase significantly the energy production of the WAPS is taken into account in this tool. CRAIN can provide weather routing services.

Ship

Ship type

Besides the thrust, the WAPS generates a large side (transverse) force which need to be balanced by the hydrodynamics of the hull, inducing leeway and extra drag.

In SimWAPS, the hydrodynamic balance and associated drag is assessed on the bases of the main characteristics of the ship (hull length and draft).

Length [m] : 0

Ship length

Ship length is mainly used to propose a set of consistent ship characteristics, depending on the selected ship type.

From a performance point of view the hull length itself has little influence on the performances of the WAPS.

However the underwater side area of the hull influences the leeway angle.

Ship Speed [kts] : 0

Ship speed

The apparent wind seen by the WAPS is a combination of the actual wind speed (over ground) and the ship's speed.

Increasing ship speed increases apparent wind speed and reduces apparent wind angle. This generally tends to increase WAPS energy production.

Beware of the impact of ship speed on fuel consumption! An optimum must be found.

Beam [m] : 0 Draft [m] : 0 Upper Deck Height [m] : 0

Online Documentation Main page (reset)

Potential Saving of Wind Propulsion

SimWAPS is a tool to assess the potential benefit of WAPS (Wind Auxiliary Propulsion System) at an early stage. The objective of this tool is to provide an order of magnitude of the production of energy of a WAPS as well as the associated saving of CO₂ and to show the influence of the various parameters.

Aerodynamic properties of the various solutions are the basis of the performance of a WAPS. CRAIN has a strong experience of wind propulsion and a large background of various aerodynamic technologies which have been used to derive aerodynamic performance of the various WAPS available in SimWAPS.

The user must keep in mind that actual performance of a WAPS relies on many aspects such as the quality of the building, structural behavior and constraint, interactions with surrounding objects, dynamic effects, control,… So the actual performance of various systems, even based on the same concept depend on the set-up on board and may vary from one provider to another. That's why the tool proposes a range of performance for each WAPS technology. The target is to get realistic and convervative figures.

In order to keep this online tool convenient, several assumptions have been made. On demand, a specific study can be carried out by CRAIN in order to take into account properly all the features of your project. Please contact us.

Select your configuration

CLmax

Area

Span

Number of devices

CLmax

Area

Span

Number of devices

CLmax

Area

Span

Number of devices

CLmax

Area

Span

Number of devices

CLmax

Diameter

Span

Number of devices

CLmax

Area

Span

Number of devices

Operating CL

Lift to drag ratio

Area

Elevation

Route

Ship type

Ship length

Ship speed

Potential Saving of Wind Propulsion

CL_max

CL_max

CL_max

CL_max

C_Lmax

CL_max