A self-propelled model power similarity design method for super high-speed planing craft

Abstract

The application discloses a self-propelled model power similarity design method of a super-high-speed planing boat, and relates to the ship technology field.The method estimates a model power system according to static water towing test data after a self-propelled model is manufactured, then carries out static motion test and dynamic planing test on the self-propelled model loaded with the model power system to obtain a change curve of a throttle lever operating position with time, a change curve of a speed with time and a relationship curve of the throttle lever operating position and static thrust, and then determines a static thrust correction coefficient through a data analysis method to correct the static thrust of the self-propelled model, and directly carries out power similarity design according to a thrust similarity criterion, which is favorable to improving the precision and practicability of the self-propelled model power similarity test of the super-high-speed planing boat, and can meet the design requirements of the power system of the super-high-speed planing boat and the self-propelled model.

Description

Technical Field

[0001] This application relates to the field of ship technology, and in particular to a dynamic similarity design method for a self-propelled model of an ultra-high-speed planing boat. Background Technology

[0002] Hypersonic planing boats utilize the principles of airfoils, relying on aerodynamic lift to support all or most of their weight, raising the hull above the water. However, a small portion of the weight remains supported by hydrodynamic lift, ensuring the boat remains on the water's surface. To guarantee the performance of hypersonic planing boats, a self-propelled model is often built during the design phase for self-propelled model testing. This testing requires ensuring similarity between the self-propelled model and the actual hypersonic planing boat. This similarity primarily includes geometric and dynamic similarity. Geometric similarity is easily determined and achieved based on the model's scale ratio. However, dynamic similarity involves challenges such as propeller-engine matching, similarity processing between the self-propelled model's fixed-pitch propeller and the actual boat's variable-pitch propeller, and the inability to conduct fuel engine tests in a laboratory. This makes it difficult to implement dynamic similarity methods, such as thrust similarity criteria, for designing the dynamic similarity relationship between the self-propelled model and the actual boat.

[0003] Under the premise of the Fu Rude similarity criterion, it can be considered that similarity in advance coefficient (or speed), power output, and thrust between a self-propelled model and a real ship is equivalent. Therefore, given the difficulty in implementing the thrust similarity criterion, the common approach at present is to use the power output similarity method for power similarity relationship design: first, a still water towing test is conducted on the self-propelled model to obtain a power output estimate; then, a certain power margin is added to this power output estimate to obtain the self-propelled model's power system estimate; finally, the power output similarity criterion is used to extrapolate to the real ship to obtain the real ship's power system estimate. However, due to the scale effect, characteristics, and manufacturing errors of the self-propelled model, similarity in advance coefficient (or speed) and power output may not actually represent thrust similarity. This leads to a large error in the designed power similarity relationship, resulting in poor practicality and low accuracy of the self-propelled model's power similarity test results. Summary of the Invention

[0004] To address the aforementioned problems and technical requirements, the applicant proposes a dynamic similarity design method for the self-propulsion model of a high-speed planing boat. The technical solution of this application is as follows:

[0005] A dynamic similarity design method for a self-propelled model of a high-speed planing boat, the method comprising:

[0006] A self-propelled model of the ultra-high-speed planing boat was made according to the scale ratio λ.

[0007] A still water towing test was conducted on the self-propelled model to obtain still water towing test data. Based on the still water towing test data, the model power system that meets the power requirements of the self-propelled model was estimated.

[0008] Static motion tests were conducted on the self-propelled model equipped with the model power system to obtain the relationship curve between the throttle lever control position and the static thrust of the model power system.

[0009] Dynamic taxiing tests were conducted on the self-propelled model equipped with the model power system to obtain the curves of the throttle control position and the speed over time during the dynamic taxiing test.

[0010] Based on the curves showing the changes in throttle position over time, the curves showing the changes in speed over time, and the curves showing the relationship between throttle position and static thrust, the minimum residual thrust ΔT when the self-propelled model breaks through the drag peak is determined. m0 The static thrust T at the peak of resistance j1 Static thrust T during cruise j2 And the static thrust correction factor K was calculated. m ;

[0011] Using the static thrust correction factor K m Static thrust T during cruise j2 After making corrections, the corrected thrust T of the self-propelled model in cruise mode is obtained. m =T j2 ×K m ;

[0012] Based on T s =λ- 3 T m The thrust similarity criterion determines the dynamic similarity relationship between the actual ultra-high-speed planing boat and the self-propelled model with the onboard model's power system. s It is the thrust of an ultra-high-speed planing boat in cruise mode.

[0013] A further technical solution involves calculating the static thrust correction coefficient K. m include:

[0014] Calculate the static thrust difference ΔT j0 =T j1 -T j2 ;

[0015] The static thrust correction factor was calculated.

[0016] A further technical solution involves determining the minimum residual thrust ΔT when the self-propelled model breaks through the drag peak. m0 The static thrust T at the peak of resistance j1 Static thrust T during cruisej2 include:

[0017] The minimum residual thrust ΔT when the self-propelled model breaks through the drag peak is determined based on the curves of throttle position and speed over time. m0 The throttle lever position when breaking through the resistance peak and the throttle lever position during cruise.

[0018] Determine the static thrust T corresponding to the throttle position when the self-propelled model breaks through the drag peak in the curve relating throttle position to static thrust. j1 And determine the static thrust T corresponding to the throttle position in the curve relating the throttle lever control position to the static thrust in the self-propelled model during cruise. j2 .

[0019] A further technical solution involves determining the minimum residual thrust ΔT when the self-propelled model breaks through the drag peak. m0 The throttle lever positions when breaking through the resistance peak and during cruise control include:

[0020] The curve of speed versus time is transformed to obtain the curve of acceleration a versus speed, and based on ΔT m The relationship between ΔT and am yields the residual thrust ΔT. m The curve showing the change in speed, where m is the mass of the self-propelled model;

[0021] Based on the curve of acceleration a versus speed and residual thrust ΔT m The curves showing the change in speed determine the time period during which the autonomous model breaks through the drag peak and the time period during cruise, and also determine the minimum residual thrust ΔT at the time when the autonomous model breaks through the drag peak. m0 And the throttle position, and determine the throttle position of the self-propelled model during the cruise period.

[0022] The further technical solution is to conduct dynamic taxiing tests on the self-propelled model equipped with the model power system, including controlling the model power system to drive the self-propelled model to conduct several consecutive complete voyages of dynamic taxiing tests. In the first complete voyage of dynamic taxiing test, the self-propelled model successively experiences the zero-speed start-up phase, the acceleration phase, the peak resistance phase, the throttle return phase, and the cruise phase. In the remaining complete voyages of dynamic taxiing test, the self-propelled model successively experiences the acceleration phase, the peak resistance phase, the throttle return phase, and the cruise phase.

[0023] Determine the time period during which the self-propelled model breaks through the drag peak and the time period in cruise mode, including during the dynamic taxiing test of each complete voyage:

[0024] Determine the curve of acceleration a as a function of speed and the remaining thrust ΔT.m The period during which the curves of change with speed all reach their minimum values ​​represents the period when the self-propelled model breaks through the drag peak. The remaining thrust ΔT of the self-propelled model before breaking through the drag peak is also considered. m Both acceleration *a* and velocity *a* decrease with increasing speed. The remaining thrust ΔT of the self-propelled model after breaking through the drag peak is... m And acceleration 'a' increases with increasing speed;

[0025] After determining the period following the time when the self-propelled model breaks through the drag peak, the remaining thrust ΔT m The period during which both acceleration 'a' and acceleration 'a' decrease to the corresponding fluctuation range is the period during which the autonomous model is in cruise mode.

[0026] A further technical solution involves determining the minimum residual thrust ΔT at the point in time when the self-propelled model breaks through the drag peak. m0 The throttle lever position, and determining the throttle lever position of the autonomous model during the cruise phase, includes:

[0027] Determine the throttle position corresponding to the time period when the self-propelled model breaks through the drag peak in the curve of the dynamic taxiing test during the current complete voyage, and the throttle position corresponding to the time period of cruise state.

[0028] Determine the speed corresponding to the time interval when the self-propelled model breaks through the drag peak in the speed change curve during the dynamic taxiing test of the current complete voyage, and determine the speed at the remaining thrust ΔT. m The minimum residual thrust ΔT corresponding to the curve of change with speed m0 .

[0029] Its further technical solution involves conducting static motion tests on the self-propelled model equipped with the model's power system, including:

[0030] The self-propelled model was fixed on a land test bench. The throttle position of the model's power system was controlled, and the speed of the model's power system was determined. The thrust generated by the model's power system was obtained through a force sensor, and the first curve of throttle position, speed and thrust was obtained.

[0031] The self-propelled model is placed in the water and moored to the shore by a mooring cable equipped with an electronic force gauge. The throttle position of the model's power system is controlled to drive the self-propelled model away from the shore. The rotational speed of the model's power system and the tension generated by the model's power system are determined by the electronic force gauge, and a second curve of throttle position, rotational speed and tension is obtained.

[0032] By combining the first and second curves, the relationship curve between the throttle lever position and the static thrust of the model's power system is obtained.

[0033] A further technical solution involves estimating, based on still water towing test data, the model propulsion system that meets the power requirements of the self-propelled model, including:

[0034] The lift-to-drag ratio K at which the self-propelled model breaks through the drag peak was determined based on still water towing test data. h Lift-to-drag ratio K during cruise c And determine the peak resistance velocity V h ;

[0035] Based on the lift-to-drag ratio K when the self-propelled model breaks through the drag peak. h and resistance peak velocity V h The maximum power N of the self-propelled model when breaking through the drag peak was estimated. max ;

[0036] Based on the lift-to-drag ratio K during self-propelled model cruise c The cruise power N of the self-propelled model in cruise mode was estimated. c ;

[0037] Determine that the provided power meets the maximum power N. max and cruising power N c The model dynamic system.

[0038] A further technical solution involves estimating the maximum power N of the self-propelled model when it breaks through the drag peak. max include:

[0039] Estimate the thrust required for the self-propelled model to overcome the drag peak. is the horizontal acceleration of the self-propelled model at the drag peak, m is the mass of the self-propelled model, and g is the gravitational acceleration of the self-propelled model;

[0040] The maximum power output of the self-propelled model when breaking through the drag peak was estimated. η h It refers to the propeller-engine combination efficiency at low speed.

[0041] A further technical solution involves estimating the cruise power N of the self-propelled model in cruise mode. c include:

[0042] Estimate the cruise thrust required by the self-propelled model in cruise mode. m is the mass of the self-propelled model, and g is the gravitational acceleration of the self-propelled model;

[0043] Estimate the cruise power of the self-propelled model in cruise mode. V c η is the cruising speed of the self-propelled model in cruise mode. c It is the propeller-engine combined efficiency during cruise.

[0044] The beneficial technical effects of this application are:

[0045] This application discloses a dynamic similarity design method for a self-propelled model of a high-speed planing boat. After fabricating a self-propelled model equipped with a model power system, the method conducts static motion tests and dynamic planing tests to obtain the curves of the throttle position change over time, the speed change over time, and the relationship curve between the throttle position and static thrust. Then, dynamic similarity design is carried out based on the thrust similarity criterion through data analysis. This method is beneficial to improving the accuracy and practicality of the dynamic similarity test of the self-propelled model of the high-speed planing boat, and can meet the design requirements of the power system of the actual high-speed planing boat and the self-propelled model.

[0046] This application also provides a unique method for estimating the power system of a self-propelled model aircraft. In addition, when conducting static motion tests, this application conducts tests on land test benches and in water mooring scenarios, so that the obtained curve of the relationship between the throttle lever control position and static thrust can not only have high data acquisition accuracy, but also reflect the influence of water resistance, which is conducive to improving accuracy. Attached Figure Description

[0047] Figure 1 This is a flowchart of a method for dynamic similarity design of a self-propelled model according to an embodiment of this application.

[0048] Figure 2 This is a curve showing the change of residual thrust with speed obtained from a still water towing test using a pool model in an example.

[0049] Figure 3 This is a flowchart of a method for estimating the model power system used in a self-propelled model according to an embodiment of this application.

[0050] Figure 4 This is an example of a dynamic taxiing test, showing the curves of the throttle position changing over time and the speed changing over time.

[0051] Figure 5 Based on Figure 4 The curve of acceleration versus speed is obtained by converting the curve of speed versus time.

[0052] Figure 6 This application provides an embodiment for estimating the minimum residual thrust ΔT when a self-propelled model overcomes the drag peak. m0 The static thrust T at the peak of resistance j1 Static thrust T during cruise j2 The method flowchart. Detailed Implementation

[0053] The specific embodiments of this application will be further described below with reference to the accompanying drawings.

[0054] This application discloses a dynamic similarity design method for the self-propulsion model of a high-speed planing boat. Please refer to [reference needed]. Figure 1 The self-propelled model dynamic similarity design method includes the following steps:

[0055] Step 1: Construct a self-propelled model of the ultra-high-speed planing boat according to the scale ratio λ. The scale ratio λ is the ratio of the scale between the actual ultra-high-speed planing boat and the self-propelled model. In this application, the self-propelled model constructed in this step is a bare hull structure without a model propulsion system. The model propulsion system mainly includes multiple model aircraft engines. This part can refer to existing design methods that ensure geometric similarity, and will not be described in detail in this embodiment.

[0056] Generally, the displacement of the self-propelled model is initially determined based on the available model aircraft engines. Then, the displacement is determined according to the gravity similarity condition M = λ between the actual high-speed planing boat and the self-propelled model. 3 The initial scale ratio λ is determined, where M is the mass of the actual high-speed planing boat and m is the mass of the self-propelled model. Then, considering manufacturing processes and weight control, the structural design and manufacturing scheme for the self-propelled model is determined. Generally, self-propelled models are made of composite materials. Finally, based on the structural design and manufacturing scheme, the final scale ratio is confirmed, and the self-propelled model is manufactured.

[0057] Step 2: Conduct still water towing tests on the self-propelled model in a pool to obtain still water towing test data. Based on the still water towing test data, estimate the model power system that meets the power requirements of the self-propelled model.

[0058] In the still water drag test of the pool model, given the drag velocity V of the pool model... m Then, according to the Froude similarity criterion, the speed of the corresponding high-speed planing boat can be determined. The thrust T of the propeller of the actual ultra-high-speed planing boat was determined based on the propeller parameters of the actual boat. s Then follow T s =λ -3 T m The thrust similarity criterion can determine the thrust T of the propeller of the self-propelled model. m Finally, by adjusting the rotational speed of the propeller of the self-propelled model, the required thrust T of the propeller can be achieved. m This achieves a relatively ideal goal of dynamic similarity design. However, due to the presence of a water tank model, the speed and drag values ​​obtained from the still water towing test using the water tank model are mostly ideal values, and these ideal values ​​cannot yield ideal power values. During the still water towing test using the water tank model, it is required that the test trailer maintain a constant towing speed V. m The following measurement of this towing speed V mThe drag force of the submerged tank model can be measured using a dedicated force-strain gauge during a static water drag test. m Drag speed V m This can be considered the speed of the self-propelled model. At different towing speeds V... m Repeated still water towing tests were conducted on a water tank model to obtain different towing speeds V. m The corresponding remaining thrust ΔT m From this, the still water towing test data of the pool model can be obtained, that is, the residual thrust ΔT. m With speed V m The curve showing the change.

[0059] Figure 2 This illustrates the residual thrust ΔT obtained through a still water towing test using a pool model in one example. m With speed V m The change curve, from Figure 2 It can be seen that the curve has two resistance peaks, with the second resistance peak corresponding to the minimum remaining thrust ΔT. m0 .

[0060] In one embodiment, a method for estimating the model power system that meets the power requirements of the self-propelled model includes, please refer to... Figure 3 :

[0061] (1) First, determine the lift-to-drag ratio K of the self-propelled model when it breaks through the drag peak based on the still water towing test data. h Lift-to-drag ratio K during cruise c And determine the peak resistance velocity V h .

[0062] During the still water towing test of the pool model, in addition to measuring the towing speed V of the pool model... m In addition to the resistance encountered, the water tank model will also be measured at the drag velocity V. m The lift force generated by the drag can be used to calculate the drag velocity V. m The corresponding lift-to-drag ratio.

[0063] When the peak resistance velocity V h When there is no corresponding experimental data, you can follow To estimate the peak drag velocity V h g is the acceleration due to gravity, and B is the width of the ship in the self-propelled model.

[0064] (2) Based on the lift-to-drag ratio K when the self-propelled model breaks through the drag peak. h and resistance peak velocity V h The maximum power N of the self-propelled model when breaking through the drag peak was estimated. max .

[0065] This includes first estimating the thrust required for the self-propelled model to overcome the drag peak. It is the horizontal acceleration of the self-propelled model at the drag peak, and Not less than 0.06g, generally taken as... Then, the maximum power output of the self-propelled model when breaking through the drag peak was estimated. η h It refers to the propeller-engine combination efficiency at low speed.

[0066] (3) Based on the lift-to-drag ratio K during autonomous driving model cruise c The cruise power N of the self-propelled model in cruise mode was estimated. c This includes estimating the cruise thrust required by the self-propelled model in cruise mode. Then, the cruise power of the self-propelled model in cruise mode is estimated. V c η is the cruising speed of the self-propelled model in cruise mode. c It is the propeller-engine combined efficiency during cruise.

[0067] (4) Determine that the provided power satisfies the maximum power N. max and cruising power N c The model's propulsion system includes determining the number of model aircraft engines needed. It also determines whether the model's propulsion system can meet the maximum power N required to overcome the drag peak. max Cruise power N in cruise mode c This also allows us to determine if the power output of the model's propulsion system has any margin. Based on the estimation, the required power for the self-propelled model is known, and we can then select a model engine to see if it meets the requirements, ensuring that the model engine can provide sufficient power.

[0068] After constructing the self-propelled model and determining its propulsion system, static motion tests (step 3) and dynamic taxiing tests (step 4) can be conducted on the self-propelled model equipped with the propulsion system. There is no specific order for these tests. Regardless of the test format, the following preparations are necessary: ​​debugging the model's propulsion system, checking the remote control equipment, detecting the data transmission status of the flight control panel, calibrating the sensitivity of the servo motors, checking the hull structure, center of gravity, and center of buoyancy, measuring environmental parameters (wind direction, wind speed, wave height, and temperature), assigning responsibilities to test personnel, and specifying safety measures. The remote control equipment for the self-propelled model is a multi-channel aircraft remote control device with high anti-interference performance, ensuring reliable operation of the model's control surfaces and throttle within visual range. The throttle position and attitude data of the self-propelled model can be recorded via the flight control panel installed within the model. This attitude data includes speed, pitch angle, roll angle, and vertical acceleration.

[0069] Step 3: Conduct static motion tests on the self-propelled model equipped with the model power system to obtain the relationship curve between the throttle lever control position and the static thrust of the model power system.

[0070] In static motion tests, the self-propelled model is kept stationary while the throttle lever position of the model's power system is controlled to determine the relationship curve between the throttle lever position and static thrust. In one embodiment, the following two static motion tests are conducted:

[0071] (1) Fix the self-propelled model on the land test bench, control the throttle position of the model's power system, determine the speed of the model's power system, and obtain the thrust generated by the model's power system through the force sensor to obtain the first curve of throttle position, speed and thrust.

[0072] When conducting static motion tests using a land-based test rig, the thrust generated by the model's power system can be measured using relatively accurate force sensors, and the rotational speed of the model's power system can be measured very easily.

[0073] (2) Set the self-propelled model in the water and moor it to the shore with a mooring cable equipped with an electronic force gauge. Control the throttle position of the model's power system to drive the self-propelled model away from the shore. Determine the speed of the model's power system and obtain the tension generated by the model's power system through the electronic force gauge. Obtain the second curve of throttle position, speed and tension.

[0074] When conducting static motion tests via mooring trials, the measured tension of the model's propulsion system has a relatively large error, and since the rotational speed of the model's propulsion system remains constant, it often requires test personnel to jump into the water to take measurements. However, compared to the first curve obtained from static motion tests conducted on land-based test rigs, the second curve obtained from mooring trials can better reflect the impact of water resistance experienced by the self-propelled model in water.

[0075] By combining the first and second curves, the relationship between the throttle lever position and static thrust of the model's power system can be obtained. The specific method for combining the first and second curves can be achieved through practical experience.

[0076] Step 4: Conduct a dynamic taxiing test on the self-propelled model equipped with the model propulsion system to obtain the curves showing the change of throttle position and speed over time during the dynamic taxiing test. The dynamic taxiing test involves placing the self-propelled model equipped with the model propulsion system in the water in a free state, controlling the throttle position of the self-propelled model, and driving the self-propelled model to navigate freely in the water.

[0077] In this application, when conducting dynamic taxiing tests on a self-propelled model equipped with a model power system, it is necessary to ensure that the self-propelled model covers a complete voyage from takeoff, acceleration taxiing to cruise state. In one embodiment, the model power system is controlled to drive the self-propelled model to conduct several consecutive complete voyages of dynamic taxiing tests. In the first complete voyage of dynamic taxiing test, the self-propelled model sequentially experiences the zero-speed takeoff stage, acceleration stage, peak drag breaking stage, throttle return stage, and cruise state stage. In the remaining complete voyages of dynamic taxiing test, the self-propelled model sequentially experiences the acceleration stage, peak drag breaking stage, throttle return stage, and cruise state stage.

[0078] Simultaneously, during the dynamic taxiing test, it is also necessary to record the throttle position change curve over time, the speed change curve over time, the distance traveled at each stage, and the attitude data of the self-propelled model throughout the entire dynamic taxiing test. In one example, the control model's power system drove the self-propelled model to continuously conduct six complete voyages of dynamic taxiing tests, and the obtained throttle position change curve over time is as follows: Figure 4 As shown in (a) above, the obtained speed change curve over time is as follows: Figure 4 As shown in (b) of the diagram.

[0079] from Figure 4 It can be seen that the throttle lever is at 100% (i.e., pushed all the way down) only occurs during the zero-speed start-up phase. During this period, the self-propelled model has the greatest starting acceleration. The speed of the self-propelled model changes differently depending on the throttle lever position. When the throttle lever position is zero, the speed of the self-propelled model remains constant. When the throttle lever position fluctuates, the speed of the self-propelled model also fluctuates. Therefore, the degree of change in the throttle lever position is basically in one-to-one correspondence with the acceleration of the self-propelled model's speed and the degree of change in the acceleration process.

[0080] Step 5: Based on the curves showing the change of throttle position over time, the change of speed over time, and the relationship between throttle position and static thrust, determine the minimum residual thrust ΔT required for the self-propelled model to overcome the drag peak. m0 The static thrust T at the peak of resistance j1 Static thrust T during cruise j2 .

[0081] First, by analyzing the curves of throttle position change over time and speed change over time, the minimum residual thrust ΔT when the self-propelled model breaks through the drag peak can be determined. m0 The throttle position when breaking through the resistance peak and the throttle position during cruise.

[0082] Similar to the still water towing test using a pool model, this application also needs to obtain the remaining thrust ΔT after conducting the dynamic gliding test. m With speed V m The curve of the change also needs to be obtained to obtain the thrust value at the moment of breaking the drag peak and the thrust value in cruise mode. Since acceleration is the residual thrust ΔT m The resulting acceleration, i.e., the acceleration of the self-propelled model. Therefore, the remaining thrust ΔT m =am, so after knowing the curve of acceleration a as a function of speed, the remaining thrust ΔT can be obtained by increasing the coefficient m. m The curve of speed versus time. Therefore, in this step, the curve of speed versus time is first converted into the curve of acceleration a versus speed, and then based on ΔT... m The relationship between ΔT and am yields the residual thrust ΔT. m With speed V m The curve showing the change.

[0083] based on Figure 4 The speed-time curve in example (b) can be converted into the acceleration-speed curve, as shown below. Figure 5 As shown. Comparison Figure 5 and Figure 2 It can be seen that the two curves are very similar in shape, which explains why the residual thrust ΔT can be obtained by using the curve of acceleration a as a function of speed. m The curve showing the change with speed is feasible and reliable.

[0084] Then, based on the curve of acceleration a versus speed and the remaining thrust ΔT, it is possible to... m The speed variation curve determines the time period during which the self-propelled model breaks through the drag peak and the time period during which it enters the cruise state; that is, it determines in which time period the self-propelled model breaks through the drag peak and in which time period it enters the cruise state. Based on the dynamic taxiing test process of the self-propelled model in each complete voyage, it is known that after takeoff, continuously increasing the throttle position causes the speed of the self-propelled model to continuously increase and enter the acceleration phase. When the speed of the self-propelled model increases to near the drag peak, the remaining thrust ΔT m As the drag decreases, the acceleration *a* also decreases. After passing the drag peak, the remaining thrust ΔT... m The acceleration 'a' increases rapidly, and when the throttle lever is retracted, the remaining thrust ΔT is reduced. m As the acceleration 'a' gradually decreases and approaches zero, the autonomous model enters cruise mode.

[0085] Therefore, during each complete voyage's dynamic taxiing test: the curve of acceleration a versus speed and the remaining thrust ΔT must be determined. mThe period during which the curves of change with speed all reach their minimum values ​​corresponds to the period when the self-propelled model breaks through the drag peak. Therefore, the remaining thrust ΔT of the self-propelled model before breaking through the drag peak is... m Both acceleration *a* and velocity *a* decrease with increasing speed. The remaining thrust ΔT of the self-propelled model after breaking through the drag peak is... m The acceleration *a* increases with increasing speed. Then, the remaining thrust ΔT is determined after the period when the self-propelled model breaks through the drag peak. m The period during which both acceleration 'a' and acceleration 'a' decrease to the corresponding fluctuation range is the period during which the autonomous model is in cruise mode, and this fluctuation range is generally around zero.

[0086] Once the time period for breaking through the drag peak and the time period during cruise are determined, the minimum residual thrust ΔT at the time when the autonomous model breaks through the drag peak can be determined. m0 For the throttle lever position and to determine the throttle lever position during the cruise phase of the autonomous model, please refer to [reference needed]. Figure 6 The flowchart shown includes: determining the throttle position corresponding to the period when the self-propelled model breaks through the drag peak in the dynamic taxiing test of the current complete voyage, and the throttle position corresponding to the period when cruising. It also determines the speed corresponding to the period when the self-propelled model breaks through the drag peak in the dynamic taxiing test of the current complete voyage, and determines the speed at the remaining thrust ΔT. m The minimum residual thrust ΔT corresponding to the curve of change with speed m0 .

[0087] Once the throttle position at the moment of breaking the drag peak and the throttle position during cruise are determined, the static thrust T corresponding to the throttle position at the moment of breaking the drag peak in the curve relating throttle position to static thrust can be determined. j1 And determine the static thrust T corresponding to the throttle position in the curve relating the throttle lever control position to the static thrust in the self-propelled model during cruise. j2 .

[0088] Step 6: Calculate the static thrust correction coefficient K. m The minimum residual thrust ΔT required for the self-propelled model to overcome the drag peak has been determined above. m0 The static thrust T at the peak of resistance j1 Static thrust T during cruise j2 Then calculate the static thrust difference ΔT j0 =T j1 -T j2 The static thrust correction factor can then be calculated.

[0089] Step 7, using the static thrust correction factor K m Static thrust T during cruise j2 After making corrections, the corrected thrust T of the self-propelled model in cruise mode is obtained. m =T j2 ×K m .

[0090] Step 8, based on T s =λ -3 T m The thrust similarity criterion determines the dynamic similarity relationship between the actual ultra-high-speed planing boat and the self-propelled model with the onboard model's power system. s This refers to the thrust of a real ultra-high-speed planing boat during cruising. As mentioned above, for the propulsion system of a self-propelled model, under the premise of the Froude similarity criterion, similarity in advance coefficient (or rotational speed), power, and thrust can be considered equivalent. However, due to the scaling effect, characteristics, and manufacturing errors of the self-propelled model, similarity in rotational speed or power may not actually represent similarity in thrust. Therefore, this application directly uses thrust similarity for simulation to design the dynamic similarity relationship, which is more reliable than the other two simulation methods.

[0091] The above descriptions are merely preferred embodiments of this application, and this application is not limited to the above embodiments. It is understood that other improvements and variations that can be directly derived or conceived by those skilled in the art without departing from the spirit and concept of this application should be considered to be included within the protection scope of this application.

Claims

1. A method for self-propelled model power similarity design of super high speed planing craft, characterized in that, The self-propelled model power similarity design method comprises: According to the scale ratio Making a self-propelled model of a full-scale super high-speed planing boat; carrying out a static water towing test on the self-propelled model to obtain static water towing test data, and estimating a model power system meeting the power requirement of the self-propelled model according to the static water towing test data; carrying out a static motion test on the self-propelled model with the model power system to obtain a relationship curve between the throttle lever operating position and the static thrust of the model power system; carrying out a dynamic sliding test on the self-propelled model with the model power system to obtain a curve of the throttle lever operating position changing with time and a curve of the speed changing with time during the dynamic sliding test; According to the throttle lever operating position-time curve, the speed-time curve and the throttle lever operating position-static thrust curve, the minimum residual thrust of the self-propelled model when breaking through the peak resistance is determined , the static thrust when breaking through the peak resistance , the static thrust in the cruising state , the static thrust difference is calculated , and the static thrust correction coefficient is calculated ; using the static thrust correction coefficient correcting the static thrust in the cruising state to obtain a corrected thrust of the self-propulsion model in the cruising state ; Based on the thrust similarity criterion, the dynamic similarity between the full-scale super high-speed planing craft and the self-propelled model with the model power system is determined, is the thrust of the full-scale super high-speed planing craft in the cruising state.

2. The self-propelled model power similarity design method according to claim 1, characterized by, the minimum residual thrust at which the self-propelled model breaks through the resistance peak the static thrust at which the resistance peak is broken through the static thrust in the cruising state comprises determining a minimum residual thrust at which the self-propulsion model breaks through the resistance peak from the change curve of the throttle lever control position over time and the change curve of the sailing speed over time the throttle lever control position at which the resistance peak is broken through and the throttle lever control position in the cruising state determining a static thrust corresponding to a throttle lever operating position at which the self-propelled model breaks through the peak of the resistance , and determining a static thrust corresponding to a throttle lever operating position at which the self-propelled model is in a cruising state .

3. The self-propelled model power similarity design method according to claim 2, characterized by, the determining of the minimum residual thrust at which the self-propelled model breaks through the resistance peak the throttle lever operation position at which the resistance peak is broken through and the throttle lever operation position in the cruising state include The curve of the change of the speed with time is converted to get the acceleration The curve of the change of the speed with time is converted to get the acceleration The curve of the change of the speed with time is converted to get the acceleration The curve of the change of the speed with time is converted to get the acceleration is the mass of the self-propelled model; Based on acceleration A curve of variation with speed and residual thrust The curve of variation with speed determines the period in which the self-propulsion model breaks the resistance peak and the period in which it is in cruising condition, and determines the minimum residual thrust at the period in which the self-propulsion model breaks the resistance peak And the throttle lever operating position, and determines the throttle lever operating position of the self-propulsion model in the period in which it is in cruising condition.

4. The self-propelled model power similarity design method according to claim 3, characterized in that, the dynamic sliding test on the self-propelled model with the model power system comprises controlling the model power system to drive the self-propelled model to continuously perform a dynamic sliding test for several complete voyages, wherein the self-propelled model successively experiences a zero-speed starting stage, an acceleration stage, a resistance peak breakthrough stage, a throttle lever retraction stage and a cruising state stage in the first complete voyage dynamic sliding test, and successively experiences the acceleration stage, the resistance peak breakthrough stage, the throttle lever retraction stage and the cruising state stage in each of the remaining complete voyage dynamic sliding tests; the determination of the time period of the self-propelled model breaking through the resistance peak and the time period in the cruising state comprises, during the process of each complete voyage dynamic sliding test: determining the acceleration the curve of the residual thrust as a function of the speed of the vessel the period in which both curves take a minimum value is the period in which the self-propulsion model breaks the peak of resistance, the residual thrust of the self-propulsion model before the period in which it breaks the peak of resistance and the acceleration decrease as the speed of the vessel increases, the residual thrust of the self-propulsion model after the period in which it breaks the peak of resistance and the acceleration increase as the speed of the vessel increases; determining that a period of time after the self-propelled model breaks through the peak resistance and acceleration both drop to a period of time within the corresponding fluctuation range is a period of time when the self-propelled model is in a cruising state.

5. The self-propelled model power similarity design method according to claim 4, wherein, said determining the minimum residual thrust at the time period of the self-propelled model breaking through the resistance peak and the throttle lever operation position, and determining the throttle lever operation position of the self-propelled model in the time period of being in the cruising state comprises: determining the throttle lever operating position corresponding to the time period of the self-propelled model breaking through the resistance peak and the throttle lever operating position corresponding to the time period in the cruising state in the curve of the throttle lever operating position changing with time during the process of the current complete voyage dynamic sliding test; determining a speed in the course of the dynamic sliding test of the current complete voyage corresponding to the period of time in which the self-propulsion model breaks through the peak of resistance, and determining the speed in the remaining thrust corresponding to the minimum remaining thrust with the change of speed .

6. The self-propelled model power similarity design method according to claim 1, wherein, the static motion test on the self-propelled model with the model power system comprises: fixing the self-propelled model on a land test bench, controlling the throttle lever operating position of the model power system, determining the rotating speed of the model power system, and obtaining the thrust generated by the model power system through a force sensor to obtain a first curve of the throttle lever operating position, the rotating speed and the thrust; setting the self-propelled model in water and mooring it to the shore through a mooring cable with an electronic force gauge, controlling the throttle lever operating position of the model power system to drive the self-propelled model to move away from the shore, determining the rotating speed of the model power system, and obtaining the pulling force generated by the model power system through the electronic force gauge to obtain a second curve of the throttle lever operating position, the rotating speed and the pulling force; comprehensively obtaining the relationship curve between the throttle lever operating position and the static thrust of the model power system from the first curve and the second curve.

7. The self-propelled model power similarity design method according to claim 1, wherein the estimation of the model power system meeting the power requirement of the self-propelled model according to the static water towing test data comprises: determining the lift-drag ratio of the self-propelled model at the time of breaking through the resistance peak according to the data of the calm water towing test , the lift-drag ratio at cruising , and determining the resistance peak speed ; The lift-drag ratio of the self-propelled model when breaking through the resistance peak and the resistance peak speed , the maximum dynamic power of the self-propelled model when breaking through the resistance peak is estimated ; lift-to-drag ratio of the self-propelled model when cruising estimated cruising power of the self-propelled model in cruising condition ; determining that the provided power meets the maximum motive power and the cruise motive power of the model motive system.

8. The self-propelled model power similarity design method according to claim 7, wherein, the estimated maximum propulsive power of the self-propelled model at the breakthrough of the peak resistance comprising: estimating the thrust required for the self-propelled model to break through the peak of resistance , is the horizontal acceleration of the self-propelled model at the peak of resistance, is the mass of the self-propelled model, is the gravitational acceleration of the self-propelled model; The maximum dynamic power of the self-propelled model at the breakthrough of the peak resistance is estimated , is the propeller combination efficiency in low speed.

9. The self-propelled model power similarity design method according to claim 7, wherein, The estimation obtains a cruising power of the self-propelled model in a cruising state comprising: estimating a required cruise thrust of the self-propelled model in a cruise state , is a mass of the self-propelled model, is a gravitational acceleration of the self-propelled model; estimating a cruising power of the self-propelled model in a cruising state , is a cruising speed of the self-propelled model in a cruising state, is a propeller assembly efficiency in a cruising state.

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