CB/Z 216-1987 Submarine model underwater resistance and self-propulsion test procedures
Some standard content:
China State Shipbuilding Corporation Guiding Technical Document CB/Z216-87
Submarine Model Underwater Resistance and Self-Propuision
Test Procedure
Model Underwater Resistance and Self-Propuision Test Code for Submarines
Published in 1987
Approved by China State Shipbuilding Corporation
China State Shipbuilding Corporation Guiding Technical Document Submarine Model Underwater Resistance and Self-Propulsion Test Code CB/Z216-87
Modet Underwater Resistanceand Self-Propulsion Test Code ior Subnarines
Group: Ship Theory and Experiment Professional Group
This code is applicable to submarine model underwater resistance and propulsion test and the expression of its results. This code includes model and test preparation, test content, model test and its result compilation and expression. Symbols and names (see Table 1), China State Shipbuilding Corporation approved and issued special b0·75R in 1987. TFormcr.
CB/Z216-87
Propeller blade expanded area
Propeller disk area
Propeller disk ratio
Characteristic chord length at 0·75R
Appendage drag coefficient
Photogel shape drag coefficient
Conning platform enclosure drag coefficient
Friction drag coefficient
Visco-pressure coefficient
Model friction drag coefficient
Bow horizontal rudder drag coefficient
Real friction drag coefficient
Resistance conversion allowance between boat model and real boat, including surface roughness coefficient, water flow hole drag coefficient, other small protrusion drag coefficients and scale effect between real boat and boat model.
Correction factor for replacement subsidy
-10/0.5psi
Missile hatch drag coefficient
Tail energy drag coefficient
Tail stabilizer drag coefficient
Total shape drag coefficient or residual drag coefficient Actual boat drag coefficient
Total drag coefficient calculated after actual boat sea trial
CB/Z 216-87
Propeller diameter
Propeller relative diameter
Diameter ratio
Model propeller diameter
Actual boat propeller diameter
Forced self-propulsion or towing power
Forced force correction value
Total number
Gravity acceleration
Propeller working advance coefficient
Rear propeller working escape speed coefficient
Spray propeller engineering Escape speed coefficient
Equal torque method to obtain the working speed coefficient
Real boat propeller working escape speed coefficient
Equal thrust method to obtain the working advance speed coefficient
Equal thrust method to obtain the real boat working escape speed coefficientTorque coefficient
Torque coefficient of rear propeller
Rising water propeller torque coefficient
Real boat screw rack torque coefficient
Thrust coefficient
Thrust coefficient of rear propeller
CB/Z 216-87
Thrust coefficient of water-spraying propeller
Thrust coefficient of real boat propeller
Total length of boat and boat model
Subscript, represents boat width
Propeller speed
Propeller rotation speed
Average propeller speed
Model propeller speed
Model propeller speed
Real boat propeller speed
Real boat propeller speed
Propeller pitch
Pitch ratio
Effective horsepower
The received horsepower of propeller
Calculated from the effective horsepower Received horsepower
Real boat shaft horsepower
Propeller torque
Corrected value of propeller torque
Model propeller torque
Real boat propeller torque
Drag or chess-shaped drag
Bare boat body force
rpm
rpm/sec
rpm/sec
rpm/min
rpm/sec
L\MT-3
L+MT-2
L*MT-2
C0/ Z 216-87
Lightsaber resistance
Reynolds force (based on boat length)
Model resistance of the first test
Model force of the next test
Model resistance
Interference resistance of the model on the sword
Reynolds number of the screw rack
Sword resistance
Sword tip resistance
Interference resistance of the sword on the model
Mutual interference resistance between swords
Total resistance of the boat model||tt ||Total resistance of actual boat
Wet surface area
Wet surface area of hull
Wet surface area of the first test
Wet surface area of model in the next test
Total condensable surface area of model
Total wet surface area of actual boat
Propeller thrust
Corrected value of propeller thrust
Thrust reduction fraction
CB/Z216-87
Thrust reduction fraction of boat model
Model Propeller displacement
Actual boat thrust
Actual boat thrust reduction fraction
Average speed
Speed at propeller disc
Actual boat speed
Actual boat speed
Wake fraction
Correction value of effective wake
m/s
Difference between actual boat estimate and actual boat effective wake after sea trial Effective wake fraction of boat model using equal force method
Effective wake fraction of actual boat using equal thrust method
|Number of propeller blades
Axis inclination
Propulsion efficiency
Hull efficiencywwW.bzxz.Net
Model hull efficiency
Real hull efficiency
Screw propeller water dispersion efficiency
Model propeller water dispersion efficiency
Real boat propeller water dispersion efficiency
Propeller water efficiency
LMT～2
Model and test preparation
2·1 Preparation before model test
CB/Z 216-87
Relative rotation efficiency
Relative rotation efficiency of model propeller
Relative rotation efficiency of real boat propeller
Model scale ratio
Kinematic viscosity coefficient
Kinematic viscosity coefficient of fresh water during model test
Kinematic viscosity coefficient of seawater during real boat sailing
Fluid density
Fresh water density during model test
Sea water density during real boat sailing
Axle side inclination angle
2·1·1According to the main scale of the real boat, take appropriate scale to draw the cross-section line diagram and appendage line diagram of the boat model. This diagram is used as the basis for processing the model and calculating the displacement volume and wet surface area. The displacement volume and wet surface area can also be calculated on the compiled computer program. 2,1·2 The model is accurately processed based on the line diagram. The model line type must be strictly similar to the real line type. The model can be cut directly according to the linear value, or it can be roughly cut and then processed according to the pallet. 2.1,3 The attached model is strictly processed according to the model value with geometric similarity. 2.2 Basic requirements of the model
2.2.Main model material: Usually the resistance test model can be made of different materials such as wood, wax, gold and fiberglass. The self-propelled test model is generally made of wood or gold. 2.2.2 The force test model can be solid, while the self-propelled model must be hollow. In order to avoid positive buoyancy during the test of the small submarine model, the model is counterweighted. When preparing the model, space for fixing the counterweight (pressure block) must be reserved. The self-propelled test model can be counterweighted inside the self-propelled box or outside the box. It is recommended that the boat model be equipped with a negative buoyancy of 25-50kgz
The parts (sword seat) connected to the resistance instrument bracket (sword) should be fixed on the boat model in advance. Requirements for boat model acceptance: The model and the real resistance must be geometrically similar, the appearance is smooth, and the surface is smooth. Wax model surface.7.
The air bubbles and shrinkage holes should be minimized, and the surface can be painted. CB/Z 216--87
Processing accuracy: length tolerance ±3mm (3~5m model), other models are subject to tolerance ±1mm. Appendage processing accuracy: length tolerance ±1.5mm, other models are ±0.5mm, 2.2.6 Before the boat model test, all appendages should be installed on the platform, and the horizontal and vertical deviation tolerances of the center line of the appendage and the center line of the boat are ±0.4\
2-3 Preparation of propeller model
Prepare according to the relevant regulations.
2.4 Preparation before propeller model test
2.4.1 The boat model should be tested in the moored state. When the current number (R.) is low. The rapid current installation is usually installed with a 1mm diameter rapid current wire at 20 meters from the head of the boat. When other rapid current wires are installed, it should be specified separately. Whether to use turbulence can be determined based on the experience of each pool. For example, when the residual resistance coefficient is obtained in the region of F r<0 · 2 5 (3 ~5 m model), turbulence is usually required because R <107. When the residual resistance coefficient is obtained in the region of F> (1·0～1·2), the Reynolds number is relatively high, that is, Re>2×1 ?, and turbulence can be omitted.
2··2 Currently, turbulence is not applied to appendages and paddle models. 2,4·3 If a mechanical resistance meter is used for resistance test, the boat model can be fixed to a solid sword. If an electric resistance meter is used for resistance or self-propulsion test, a hollow sword must be connected to the boat model. The sword must be strictly calibrated and installed. Ensure that the section deflection angle $1n is <1/100 (usually the front and rear edges of the sword section are allowed to be 1mm㎡ away from the same reference line). In each round of test, the sword resistance and its dry batch resistance are deducted. For electric force gauges, when the force measuring element is installed in the surface of the model, it is possible to avoid measuring the resistance of the model. However, the interference resistance of the model to the model should be taken into account (unless the interference is small enough to be ignored). 2. to 4. Before the boat model is transported into the dock, the surface of the boat model must be wiped clean. The spider used for resistance test is soaked for more than 24 hours, then the mucus on the surface is cleaned and wiped clean. The surface is sprayed with paint, and no soaking is required. 2.4.5. Preparation of inflatable floats: When the boat model is transported to the dock, it needs to be floated by an inflatable float to be transported into the dock. Close the dock door and pump water to lower the boat model to the installation position for installation. After the installation is completed, the float leaves the boat model. Then, the dock is filled with water, and the dock door can be opened for testing.
The boat model is usually installed upside down on the boat, that is, the keel faces up and the appendages such as the command platform face down. 2.4.6
When the boat model is connected to the trailer support (sword), the boat longitudinal center scraping surface is required to be consistent with the forward direction, and the model baseline is parallel to the still water surface. It is usually controlled by adjusting the two supports. At the D station and the 20 station, the deviation of the bow and stern from the center line and the stern longitudinal tilt from the baseline are allowed to be ±1.5 μm. The distance between the guide rail of the support and the keel of the boat model should be large enough to avoid or reduce the interference of the different leveling on the model. 2.4.8
2, the relative diving depth H/up of the boat should be as large as possible to avoid and reduce the influence of surface waves. 2.4.1αIn order to avoid the shock caused by the inertia force of the boat model when the trailer starts and brakes, the dynamic instrument (support) must be equipped with a brake device. When the model accelerates to the test speed, the brake is turned on, and the vehicle speed is stabilized and the record is recorded. After the recording is completed, the brake is applied before stopping.
3 Test content
3-1 Resistance test
Steel resistance test after deducting the resistance of the hull and its interference 3.1.1
3.1,2 Resistance test with all appendages installed, the purpose is to determine the total resistance of the whole boat and its coefficient, and remove the bow horizontal rudder, command platform enclosure, missile compartment, tail stabilizer and tail rudder body one by one to obtain the resistance coefficient of each appendage and the hull
3,! ·4 Resistance test of submarine appendage model The electric resistance meter can also be installed in the appendage model to directly measure the resistance of the appendage that interferes with the hull. A separate appendage resistance test can also be carried out to obtain the ideal solution. 3.2 Water test
The test content is determined according to the design and research purpose and the specific requirements of the self-propelled test. 3.3 Self-propelled test
Sword force test (with conductivity, corresponding to the diving depth of the boat test) Total resistance test of the model (with all appendages) Water-splashing test of the propeller used in the self-propelled test
Self-propelled test is divided into two types: strong pursuit self-propelled test and pure release self-propelled test. At present, the former is mostly used. The latter can also be used when the electric measurement technology and automatic tracking test technology are mature. 4 Test requirements
: 4.1 General requirements for the test
The test pool should be a deep water pool to ensure that the potential model has a certain diving depth. Before the formal test record, the boat and propeller model must be pre-towed 1 to 2 times to keep the water conditions of each test pool basically based on 4.1.2
. For this reason, there should be a certain time interval between the two tests. 4.1.3 The test model should be tested under the condition of stable flow state. The record must be made under the condition of stable trailer speed and propeller speed, and a certain recording time is required. Before and after the test, the pool water temperature corresponding to the center depth of the boat model should be measured on the measuring plate section. 4.1.4
After the test, the boat model should be inspected for broken paint or paint peeling and accessories damage. This will help analyze the test results.
4.2 Resistance test
The resistance test requires the test to be carried out until the residual resistance coefficient of the model tends to a constant. When an electric resistance meter is selected, a resistance meter with an appropriate range can be selected based on the estimated boat model resistance. 4.2.2
4.2.3 In the absence of surface wave influence. After the resistance coefficient tends to a constant, the test points are more than 5 points, and the test points of a resistance curve should not be less than 12 points.
4·2·4 The measuring disk accuracy requirement of the resistance meter is D·5%, and the fluctuation value when the boat model towing speed is 1 unit/s should be less than 0.3%.
Test accuracy: The average error of the boat transverse resistance test result should be less than 1%. 4.2.5
4·3 Propeller water splash test
The test shall be carried out according to the corresponding test procedures.
4·4 Boat model self-propulsion test
The self-propulsion instrument shall be calibrated (static or dynamic) before and after the self-propulsion test, including the 4.4.1
calibration of the measuring disk instrument used in the test.
2 During the self-propulsion test, the friction torque of the shaft system shall be deducted, usually by zeroing with propeller transmission or without propeller separation speed (corresponding to the speed of the self-propulsion test).
4,4.3 During the self-propulsion test, the load range of the propeller of the rear model should correspond to the load range of the real propeller, or keep the two close. The Reynolds number of the propeller model at the rear of the boat should be kept basically the same as the Reynolds number of the water-jetting propeller, so that the flow pattern on the blades of the two is basically the same. Usually, the Reynolds number of the water-jetting propeller model is:
bo·15R
+(0.75nD)
>3·0xl05
CB/Z 21687
4·生·4 After the trailer is started, when the towing speed, propeller speed and force are stable, the advance speed, speed force, thrust and torque are recorded from time to time. The equal speed method is usually used for the self-propulsion test of the forced pursuit. At the same speed, the propeller speed is changed at least 4 times near the self-propulsion point of the boat model, and the speed interval should be roughly the same, and the test results of each time should be recorded separately. 4.4.5 If the equal speed method is used and the tank length is not enough to ensure that a self-propulsion point is made in one voyage, the errors of each value caused by the speed error of each time shall be corrected, and the correction can be made according to the following formula: V
waypoint.
For each state of self-propulsion test, there should be no less than 5 self-propulsion points, that is, it is necessary to reasonably select several drag speeds. Find out the respective.4.6
Measurement accuracy: The static calibration accuracy of the self-propulsion instrument, the thrust is 0.3%, the torque is 3%, and the speed is 0.3% under the condition of 101/g
4.8 In the pure self-propulsion test, when the drag speed is stable, the propeller speed automatically follows the propeller, so that the thrust from the propeller is balanced with the boat resistance, and the thrust, torque, speed and drag speed are recorded at the same time. Pure sudden self-propulsion can save the measurement of resistance and record of forced force. Expression of test data and actual boat prediction
6.1 Expression of resistance test results
5.1.1 The results of submarine model resistance test are given in the form of resistance speed curve and resistance coefficient - Tenon number, Froude number curve.
The original test data are uniformly given in the form of Table 2 "Model force test record table", and the resistance coefficient is uniformly given in the form of Table 3.5.1.2
“Shape force coefficient calculation table” is given. Table 2
Model number
Model scale entry
Riss flow condition
Model material
Captain L
Model resistance test record
1 Test date
Tester
Water temperature t℃
Sensitivity
Drain pan
Model number
Model scale entry
Riss flow condition
Model material
Captain L
Diving depth H
Test date
Tester
Water t℃
Sensitivity
Drain pan
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