Theory Design Air Cushion Craft 2009 Part 12 pot

... characteristic of air clearance, then the operation point at various craft weights and fan speeds can be obtained as shown in Fig. 12. 13. Figures 12. 12 and 12. 14 identify the ... the cushion pressure/length ratio pjl c . Due to support of the major part of the craft weight by the cushion, an SES structure is less highly loaded and can there...

Ngày tải lên: 11/08/2014, 18:20

... with two air ducts from the air outlet of the fan have been carried out in the towing tank. Part of the outflow may be led directly into the cushion and another part via air ducts, ... of air leakage and compressibility of cush- ion air will affect the change of cushion pressure and flow rate. Figure 8.42 shows such dependency between the craft...

Ngày tải lên: 11/08/2014, 18:20

... of cushion air compression is too small to change the air flow rate and fluctuate the cushion pressure. This is not true for full-scale craft, especially for larger hovercraft ... the craft, W i the weight of various subsystems, L c , B c , H the cushion length, beam and height of the craft and N e , R, p c the engine power, range of the c...

Ngày tải lên: 11/08/2014, 18:20

... rotors Air cushion craft Jeff (A) Q-FAN Free propeller theory I I I I I I I I I I I I I 3 45678910 2 Diameter parameter (DVl.OOO/P) 3 4 5 6 7 8 9 100 Fig. 15.10 77A/vs/?/A/ 05 [4]. • cushion ... thrust developed from this air jet is T=Qp A (V } - V c ) where V c is the craft speed air speed and V } the air jet speed (15.44) 500 Propulsion system desig...

Ngày tải lên: 11/08/2014, 18:20

... pump type will vary according to the craft design speed. With exception of high speed craft, above about 60 knots, it is likely that the main design constraint will be the pump ... this design was selected for the 3KSES as a design basis. At craft speeds of 30 knots, F/F C variation between 0.5 and 0.95 can occur without cavitation on a typica...

Ngày tải lên: 11/08/2014, 18:20

... 45 1.9 SES and ACV design 46 2. Air cushion theory 48 2.1 Introduction 48 2.2 Early air cushion theory developments 50 2.3 Practical formulae for predicting air cushion performance ... invention to first application (years) Steam boat 41 Hydrofoil craft 35 Submarine 25 Hovercraft 13 Jet aircraft 12 Aircraft 8 hovercraft, focussing on the UK, fo...

Ngày tải lên: 11/08/2014, 18:20

... shape of cushion plan. For a rectangular air cushion, p s = 1 and will be the minimum, meanwhile C w will be minimum when the cushion plan is rectangular; therefore an air cushion ... craft and C w the wave-making drag coefficient. From this equation we can see that for constant cushion length / c , cushion beam B c and craft weight W, the n...

Ngày tải lên: 11/08/2014, 18:20

... achieve the designer's requirements in the speed range to 40 knots. Above this speed, an air cushion supporting most of the craft weight is most likely to give the optimum design ... post-hump speeds, because a large air flow rate will increase the air component of the two-phase flow blown from the air cushion, producing air lubrication effects...

Ngày tải lên: 11/08/2014, 18:20

... type 717 Item Symbols Dimensions 717 717A 717C Craft weight Cushion length Cushion beam Cushion lib ratio Cushion pressure length ratio Cushion pressure Flow coefficient VCG Bow and ... rigid surface whatever type of cushion compartment was adopted. 3 en Fig. 4.34 Static transverse stability of ACV models with + type of air cushion compartmentation. 170 S...

Ngày tải lên: 11/08/2014, 18:20

... deformation in SES air cushion 197 Fig. 5.8 Wave amplitude due to an ACV on shallow water in/off air cushion. 5.3 Water surface deformation in/beyond SES air cushion on calm ... to air cushion and skirt F c = jetted thrust due to air leakage from cushion during turning manoeuvre F m = air momentum force z m = distance from ground to the cent...

Ngày tải lên: 11/08/2014, 18:20