From Icing to Helipads: CFD-Based Solutions to Contemporary Rotorcraft Challenges

Adam Dziubiński

doi:10.2478/tar-2025-0009

Fig. 1.

Selected rotorcraft examples designed at the Institute of Aviation [7]: a) the JK-1 Trzmiel (1957)[2], b) the BŻ-4 Żuk (1959), c) the BŻ-1 Gil (1960), d) the IS-2 (1990), e) the ILX-27 (2012), f) the I-28 (2012).

Fig. 2.

Prototype of the ILX-27 unmanned helicopter in flight [7] and its computational model showing a pressure distribution map.

Fig. 3.

a,b) Simplified representation of the duct, c) computational model showing the finite volume mesh of the periodic cutout of one blade, along with corresponding part of the simplified duct [12].

Fig. 4.

Flowfield variation with the blade pitch angle, visualized by velocity magnitude color map and pathlines.

Fig. 5.

Mesh changes and ice layer growth on a predefined blade cross-section, viewed along the radius (with blade tip at the bottom) [12].

Fig. 6.

The pressure distribution and pathlines on the blade and the duct surfaces during ice accretion [12].

Fig. 7.

Division of the model into named zones, the axial component of the aerodynamic force for the individual zones, and a total summary component [12].

Fig. 8.

The aerodynamic force and moment components calculated at the center of the hub for one blade of the tail rotor [12].

Fig. 9.

The three views of the I-28 autogyro [13].

Fig. 10.

Visualization of the rotor wake on a set of cross sections behind the propeller, and yawing moment coefficient as a function of sideslip angle [13]. The propeller wake at β=25° of sideslip angle (bottom right picture) is touching only the upper side of the left V-tail, causing negative stability.

Fig. 11.

The exact geometry of autogyro (above) compared to the one used for the preflight calculations (below), and a cross section through the tail surface including the gap geometry between the tail stabilizer and the rudder [13].

Fig. 12.

Separation areas (reverse flows) appearing at the β=−10° sideslip angle.

Fig 13.

Analyzed modifications of the tail: upper left base geometry, extended ruder, and extended stabilizer (left), short and long tailplane and the Xenon autogyro in the same scale (right) [13].

Fig 14.

The yawing moment characteristics vs. sideslip angle of the tested configurations [13].

Fig. 15.

Influence of ruder deflection on the yawing moment of the I-28 autogyro [13]. The dotted lines show the influence of the short tailplane on the deflected rudder, compared to flight test cases shown with continuous lines.

Fig. 16.

The Kopter SH-09 helicopter in flight [16] and its simplified 3D model [17].

Fig. 17.

Simplified version of the nacelle model compared to the complex one, including all the installations inside [17].

Fig. 18.

The velocity magnitude visualization in a set of cross sections through the nacelle. Due to proprietary information constraints, only the colormap was shown in source [17] but the scale is identical in all cross sections..

Fig. 19.

The temperature field in hover for standard and “hot&high” conditions. Due to proprietary information constraints, only the colormap was shown in source [17] but the scale is identical in all cross sections.

Fig. 20.

The temperature field in “hot&high” conditions for forward (a), backward (b) and sideways flight (c) [17].

Fig. 21.

The PZL W-3 “Sokół” helicopter hovering over the courtyard of the Royal Castle in Warsaw, Poland, and downwind over the high building with one of its main gear wheels touching the roof [18].

Fig. 22.

The vortex ring appearing during a hover over a well-shaped structure [19].

Fig. 23.

Examples of elevated helipad configurations: a) on the highest building, b) at the level of surrounding roofs c) near the highest building [20].

Fig. 24.

Helipad atop the Hospital in Katowice-Ochojec, where lifting of the helipad was analyzed [20].

Fig. 25.

Computational meshes for (a) at helipad at Copernicus Hospital in Gdansk, built on a platform at the level of surrounding roofs, and (b) a helipad built on the highest building in the vicinity, atop a hospital in Gdynia [22].

Fig. 26.

Helipad built on the same level as the surrounding roofs, where the influence of the rotor wake in hover, while rather safe on the left, will cause a partial vortex ring on the right [21].

Fig. 27.

Influence of a minimal air gap below the helipad surface on the flow quality above the helipad surface [20].

Fig. 28.

Decrease in the size of the vertical velocity zone using an air gap: a,c – blocked, b,d – 3m unblocked air gap, with the arrow showing the wind direction.

Fig. 29.

The path approaching the Gdynia Hospital from behind the “Sea Towers” building on the Gdynia waterfront, shown here emerging from the clouds, and the corresponding model in CFD [22,23]. The CFD results are shown in the plane at 3m above the helipad level and are inverted with respect to the photo.

Fig. 30.

The Gdynia Hospital Helipad: 3D model compared to the construction drawings, and the corresponding computational mesh.

Fig. 31.

The Copernicus Hospital in Gdansk – photogrammetric comparison between the model and an aerial photograph [22].

Fig. 32.

Lublin Hospital helipad – photogrammetric comparison between the 3D and LIDAR model.

Fig. 33.

Hospital in Rzeszów – overlapping LIDAR (textured) and 3D (yellow) model of whole city blocks.