CN112729760A - Pneumatic lift and pneumatic resistance coefficient combined measurement method - Google Patents
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Abstract
The invention discloses a method for jointly measuring aerodynamic lift and aerodynamic drag coefficients, which comprises the following steps: step 100: establishing a model device for a dynamic model experiment; step 200: arranging a data acquisition module on the model device, weighing the weight of the whole experimental model formed by the model device and the data acquisition module, and recording the weight as mm(ii) a Step 300: completing experiments of different speed areas on the experimental model on a dynamic model experimental device, and obtaining multiple effective experimental values; step 400: based on a plurality of acceleration values and vertical force values of the experimental model obtained by the data acquisition module, the aerodynamic lift coefficient and the aerodynamic drag coefficient of the experimental model in the dynamic model experiment process are sequentially obtained through data processing and calculation. The aerodynamic model experiment performed in the invention not only can realize the combined measurement of aerodynamic lift and aerodynamic drag coefficient, but also can complete a plurality of experiments which can not be completed by wind tunnel experiments.
Description
Technical Field
The invention relates to the technical field of pneumatic model experiments, in particular to a method for jointly measuring a pneumatic lift coefficient and a pneumatic resistance coefficient.
Background
In the general aerodynamic parameter test of vehicles or aircrafts, because the scaling models of the devices are basically equivalent in length and width, the wind tunnel can be used for carrying out related aerodynamic experiment tests, while the length of the scaling model of a high-speed train is far larger than the transverse dimension of the scaling model of the high-speed train, the wind tunnel is not suitable for carrying out related aerodynamic experiments, but the dynamic model can naturally and truly simulate the train movement on a track. In addition, for the experiment simulation related to the aspects of the train crossing the tunnel, the intersection and the like, the experiment can hardly be completed by adopting a wind tunnel experiment, and the processes can be easily simulated by a dynamic model experiment; in addition, the aerodynamic resistance and the lift force of the train in the process of passing through the long tunnel can be tested by the method, and the wind tunnel is difficult to perform the test work in the aspect.
The davis equation is used to describe the relationship between the mechanical parameters and the motion parameters of an object with a fixed shape in the process of linear application, such as a train moving on a rail, a fixed-wing aircraft flying in the air, and the like. The formal expression of the davis equation is: ma is A + BV + CDV2Where M is the mass of the model or real object, a is the acceleration of the model or real object, and V is the linear motion velocity of the model or real object. A is the kinetic friction force, typically of a model or real object, B is the coefficient of force proportional to the velocity of a model or real object, C is typically the coefficient of aerodynamic drag, which is proportional to the square of the velocity, and B is typically small.
At present, the main problem which hinders the dynamic model experiment test to replace the wind tunnel experiment test is the measurement of the aerodynamic resistance and the aerodynamic lift. In the dynamic model experiment, when the aerodynamic lift of the model can not be ignored, the influence of the aerodynamic lift of the model on the track surface pressure must be considered in the test process. Since the aerodynamic drag of the model moving on the rail follows the davis equation, and the aerodynamic lift is also proportional to the square of the velocity FL＝CLV2(mu is a dynamic friction coefficient). The pressure of the model on the orbit surface is changed due to the occurrence of the aerodynamic lift force, so that the dynamic friction resistance of the model is changed, namely the A term value in the Thevis equation is influenced; the decrease in the pressure of the model on the rail surface results in a decrease in the kinetic friction, which is expressed in the davis equation: fD＝(mg-CLV2)μ+BV+CDV2＝mgμ+BV+(CD-CLμ)V2This is the mathematical description followed of the results obtained from the actual tests.
Therefore, the aerodynamic resistance coefficient based on the davis equation test needs to consider the pressure of the aerodynamic lift force on the track surface, so that the change of the dynamic friction force is converted into the influence on the aerodynamic resistance coefficient, but at present, a method and a technology for simultaneously measuring the aerodynamic lift force, the aerodynamic resistance and the coefficient thereof in dynamic model experiments are lacked at home and abroad.
Disclosure of Invention
The invention aims to provide a method for jointly measuring the coefficient of aerodynamic lift and the coefficient of aerodynamic resistance, which aims to solve the technical problem that a method for simultaneously measuring the aerodynamic lift and the aerodynamic resistance is lacked in the prior art.
In order to solve the technical problems, the invention specifically provides the following technical scheme:
a method for jointly measuring aerodynamic lift and aerodynamic drag coefficients comprises the following steps:
step 100: establishing a model device for a dynamic model experiment;
step 200: arranging a data acquisition module on the model device, weighing the weight of an integral experimental model formed by the model device and the data acquisition module, and recording the measured weight as mm(ii) a The data acquisition module is used for acquiring data at a first time interval delta taMeasuring acceleration values of the experimental model in sequence at a second time interval deltatFSequentially measuring vertical force values of the experimental model;
step 300: completing the experiment of different speed areas of the experimental model on the dynamic model experimental device, and obtaining multiple effective experimental values;
step 400: and sequentially obtaining the aerodynamic lift coefficient and the aerodynamic drag coefficient of the experimental model in the dynamic model experimental process through data processing and calculation based on the plurality of acceleration values and the plurality of vertical force values of the experimental model obtained by the data acquisition module.
As a preferred scheme of the invention, the dynamic model experimental device comprises an acceleration section, an experimental section and a deceleration section, wherein the experimental model sequentially passes through the acceleration section, the experimental section and the deceleration section from zero speed until stopping; wherein the content of the first and second substances,
the acceleration value comprises the experimental values of the acceleration section, the experimental section and the deceleration section, which are sequentially recorded as ai(i＝1,K)，ai(i ═ K +1, M) and ai(i＝M+1,N)；
The vertical force value is the experimental value of the experimental section and is marked as Fi(i＝1,M′)；
And K represents the end point of the experimental model reaching the acceleration section, M represents the end point of the experimental model reaching the test section and represents the start of deceleration of the experimental model, and N represents the end point static state of the experimental model after the operation of the deceleration section.
As a preferred embodiment of the present invention,
in the acceleration section, the speed of the test model is increased monotonously;
in the experimental section, the speed of the experimental model slowly and uniformly decreases;
during the deceleration phase, the speed of the test model drops sharply.
As a preferable aspect of the present invention, the method for calculating the aerodynamic lift coefficient includes the steps of:
step 411, calculating a velocity value of the experimental model in the experimental section according to the first time interval and all the obtained acceleration values, and recording the velocity value as Vi(i＝K+1，M)；
Step 412, based on the relation of aerodynamic lift: fL＝CLV2Obtaining the aerodynamic lift coefficient CL＝FL/V2；
According to the principle that in aerodynamics, the aerodynamic lift force is in direct proportion to the square of the speed of an experimental model, the coefficient of the aerodynamic lift force is obtained
Conversion to dynamic model test, aerodynamic lift coefficient
Wherein, FLThe aerodynamic lift of the experimental model in the dynamic model test process is represented, and V is the speed of the model; fiThe pneumatic lift value is obtained by experimental measurement; j takes the value of the experimental model in all or one time range of the experimental section;
when Δ t is reachedFAnd Δ taWhen the values are time-synchronized and at the same frequency, then deltatF＝Δta；
In the above experimental tests CLThe discrete value expression of (a) is simplified as:
obtaining the aerodynamic lift coefficient:
step 413, calculating an average value according to a plurality of aerodynamic lift coefficients obtained by a plurality of experiments to obtain a target aerodynamic lift coefficient CL。
As a preferable aspect of the present invention, the method for calculating the aerodynamic drag coefficient includes:
step 421, calculating the average speed value V of the experimental model in the experimental sectionT，KAnd average acceleration value aT，K(ii) a Wherein K is 1 to N0And N is0The 3 is the number of experiments;
step 422, utilizing the Davis equation Ma in aerodynamics as A + BV + CV2；
To obtain a weight mmThe davis equation of the experimental model
And using the Davis equations of the experimental model and (V)T，K，aT，K) Constant values A, B and C can be obtained respectively by numerical fitting of the minimum mean square error;
step 423 using a ═ mmg mu and CD＝C+μCLThe coefficient of dynamic friction mu and the coefficient of aerodynamic drag C can be calculatedD；
Wherein, M is the mass of the experimental model or the actual object, a is the acceleration of the experimental model or the actual object, and V is the linear motion speed of the experimental model or the actual object;
a is the dynamic friction force of the experimental model or the actual object, B is the coefficient of the force of the experimental model or the actual object which is in direct proportion to the speed, C is the coefficient of the pneumatic resistance, and the pneumatic resistance is in direct proportion to the square of the speed.
As a preferred embodiment of the present invention, the method for processing data in step 411 includes:
and manufacturing a speed-time evolution curve of the experimental model according to the first time interval and all the acquired acceleration values.
Compared with the prior art, the invention has the following beneficial effects:
the invention carries out multiple times of pneumatic model experiments by adopting the pneumatic model experiment device provided with the data acquisition module, and carries out data processing on the acquired acceleration and vertical force measurement data in the motion process of the dynamic model by utilizing the relation between acceleration and speed time, the relation between lift force and speed and the combination of the davis equation, thereby realizing the combination and simultaneous measurement of the pneumatic lift force and the pneumatic resistance coefficient. Compared with wind tunnel tests, the dynamic model adopted by the invention for carrying out the pneumatic model tests can realize the combination and simultaneous measurement of the pneumatic lift and the pneumatic resistance coefficient, and the adopted dynamic model research method can complete more running conditions, including the completion of a plurality of tests which can not be completed by the wind tunnel tests, such as the simulation of the motion of a high-speed train on a track, the experiment simulation related to the aspects of train passing through a tunnel, intersection and the like, has wider speed test range, short experiment time and low cost, and provides an experiment and test basis for replacing the pneumatic test by the dynamic model.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.
FIG. 1 is a flow chart of a measurement method provided by an embodiment of the present invention;
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
At present, the main problem hindering the dynamic model experiment test to replace the wind tunnel experiment test is the measurement of aerodynamic resistance and aerodynamic lift, but the method and the technology for the combination and simultaneous measurement of aerodynamic lift and aerodynamic resistance coefficient are lacking at home and abroad at present, therefore, the invention provides a method for the combined measurement of aerodynamic lift and aerodynamic resistance coefficient, as shown in fig. 1, comprising the following steps:
step 100: and establishing a model device for a dynamic model experiment.
Step 200: arranging a data acquisition module on a model device, weighing the weight of an integral experimental model formed by the model device and the data acquisition module, and recording the measured weight as mmIt should be noted that in the experiments, mmThe value of (a) cannot be too large, which results in the absolute value of the deceleration of the experimental model in the experimental section becoming smaller; the data acquisition module is used for acquiring data at a first time interval delta taMeasuring acceleration values of the experimental model in sequence at a second time interval deltatFAnd sequentially measuring the vertical force values of the experimental model. The test instrument installed on the experimental model can not change the pneumatic appearance of the model, and because the experiment of the intrinsic dynamic model is suitable for vehicles and weapon systems moving at high speed, such as high-speed trains, racing cars, airplanes, subsonic missiles and other devices running at high speed, the direct installation of the sensor in the model is more convenient, the real-time measurement and data transmission can be realized, and the measurement result is more accurate.
Step 300: and (3) completing the experiment of different speed areas of the experimental model on a dynamic model experimental device, and obtaining multiple effective experimental values. In principle, the more the number of effective experiments is, the more accurate the aerodynamic lift and the aerodynamic drag coefficient is, and therefore, when the experiments are carried out, the average value of key data is obtained by carrying out a plurality of experiments.
Step 400: based on a plurality of acceleration values and vertical force values of the experimental model obtained by the data acquisition module, the aerodynamic lift coefficient and the aerodynamic drag coefficient of the experimental model in the dynamic model experiment process are sequentially obtained through data processing and calculation.
According to an acceleration numerical curve obtained by a dynamic model experiment, the motion process of the model experiment device in a complete experiment can be obviously divided into an acceleration section, an experiment section and a deceleration section, the dynamic model experiment device comprises an acceleration section, an experiment section and a deceleration section, the experiment model sequentially passes through the acceleration section, the experiment section and the deceleration section from zero speed until stopping, namely, the initial speed data and the final speed data of each experiment are basically equal to zero; wherein the content of the first and second substances,
in a complete experiment process, the acceleration value comprises the experiment values of an acceleration section, an experiment section and a deceleration section which are sequentially recorded as ai(i＝1，K)，ai(i ═ K +1, M) and ai(i＝M+1，N)；
The vertical force value is the experimental value of the experimental section and is marked as Fi(i＝1，M′)。
K corresponds to the end point of the acceleration process of the model and also corresponds to the model to enter an experimental section; m corresponds to the model and reaches the end point of the experimental section, and also corresponds to the model and starts to decelerate; and N corresponds to the model to be decelerated to a static state in the deceleration section.
The evolution curve of the velocity over time is obtained based on the acceleration data integration, where the integration process follows: vi＝Vi-1+aiΔtaTherefore, the speed is also characterized by the acceleration by three processes that can be clearly distinguished: an acceleration phase (speed monotonically increasing), an experimental phase (speed uniformly decreasing with a small deceleration) and a deceleration phase (speed sharply decreasing). The average speed of the experimental section may be the average of the highest speed and the lowest speed of the experimental section.
The calculation method of the aerodynamic lift coefficient comprises the following steps:
step 411, obtaining all acceleration values according to the first time intervalCalculating the speed value of the experimental model in the experimental section and recording as Vi(i＝K+1，M)；
Step 412, according to the obtained vertical force test data F of the model device in the experimental sectioni(i ═ 1, M'), the vertical force is upward positive, after the influence of gravity is removed, the data of evolution of pure lift force along with time in the experimental section is obtained, the lift force data is combined with the speed data, and according to the relation F between the aerodynamic lift force and the model speed, the data is obtainedL＝CLV2Obtaining the aerodynamic lift coefficient CL＝FL/V2。
The aerodynamic lift coefficient is obtained according to the fact that in aerodynamics, the aerodynamic lift is in direct proportion to the square of the model speed
Conversion to dynamic model test, aerodynamic lift coefficient
Wherein, FLRepresenting the aerodynamic lift of the experimental model in the dynamic model experiment process, V is the speed of the model, CLIs the aerodynamic lift coefficient, FiTaking the value of the experimental model in all or one time range of the experimental section for the pneumatic lifting value obtained by experimental measurement; Δ tFAnd Δ taThe data acquisition time step length of the force sensor and the acceleration sensor is respectively when the time step length is delta tFAnd Δ taWhen the sampling time is the same frequency and synchronous, then delta tF＝Δta；
In the above experimental tests CLThe discrete value expression of (a) is simplified as:
obtaining the aerodynamic lift coefficient:
step 413, obtaining one C in one experimentLSeveral effective experiments correspond to several CLCalculating an average value according to a plurality of aerodynamic lift coefficients obtained by a plurality of experiments to obtain a target aerodynamic lift coefficient CL。
The calculation method of the aerodynamic resistance coefficient comprises the following steps:
step 421, according to the collected acceleration data, using V1＝a1ΔtaAnd Vi+1＝Vi+aiΔtaAnd obtaining the speed data of the model device in the experimental section as follows: vi(i ═ K +1, M), and an evolution curve of the speed of the model experimental device with time, the evolution curve being substantially an oblique straight line in which the speed uniformly decreases with time, and the average speed value V of the model experimental device in the experimental section in each experiment being obtained by using the oblique straight lineT，KAnd average acceleration value aT，K，K＝1～N0And N0The number of times of experiment is more than or equal to 3.
In practical application, it should be noted that the velocity values of each experiment should have a certain dispersion and should not be too close. In addition, the speed of the model in the experimental section cannot be too small, which causes the absolute value of the deceleration of the model in the experimental section to become small due to the aerodynamic resistance, and is not favorable for solving. For the convenience of solution, the experimental section cannot be too long, if the experimental section is too long, the speed evolution of the experimental section becomes a curve, which is not beneficial to the value of the model speed and the acceleration, the fitting error is large, and the speed curve of the experimental section is usually the best inclined straight line.
In aerodynamics, davis's equation is used to describe the relationship between mechanical parameters and motion parameters of an object with a fixed shape during linear application, such as a train moving on a rail, a fixed-wing aircraft flying in the air, and the like. The formal expression of the davis equation is: ma is A + BV + CDV2，
Where M is the mass of the model or real object, a is the acceleration of the model or real object, and V is the linear motion velocity of the model or real object. A is the kinetic friction force, typically of a model or real object, B is the coefficient of force proportional to the velocity of a model or real object, C is typically the coefficient of aerodynamic drag, which is proportional to the square of the velocity, and B is typically small.
For an aircraft or a high-speed train with a fixed aerodynamic shape in a subsonic velocity range, in wind tunnel and dynamic model experiments, as long as the aerodynamic lift and aerodynamic drag coefficients of a model are obtained, the fixed shape is amplified in equal proportion, and the aerodynamic lift and aerodynamic drag values can be accurately calculated: the proportionality coefficient is equal to the square of the magnification factor of the size, i.e. to the magnification factor of the cross-sectional area: if the reduction ratio of the model is 1: 10 and the drag coefficient measured by the model is X, the aerodynamic drag coefficient of the actual object becomes 100X.
For high speed trains or fixed wing aircraft, the scaling size cannot be less than 1: 10, i.e. the size of the experimental model should not be less than 1/10 of the actual size. Therefore, the experimental data can be accurately extrapolated to the pneumatic parameter value corresponding to the actual object.
Step 422, utilizing the davis equation in aerodynamics:
FD＝ma＝A+BV+CDV2＝mgμ+BV+CDV2
to obtain a weight mmThe davis equation of the experimental model
And using the Thevis equation of the experimental model and the average velocity value and the average acceleration value (V)T，K，aT，K) Constant values A, B and C can be obtained respectively by numerical fitting of the minimum mean square error;
the solving steps of A, B and C are as follows:
firstly, according to the model speed curve, obtaining the average acceleration a of the multiple models in the experimental sectioniAnd an average velocity Vi，
Secondly, the minimum mean square error is used to obtain A, B and C,
is provided with
i represents the number of trials;
according to formula (A) ═ mmg mu and CD＝C+μCLAnd coefficient of aerodynamic drag CD。
The requirement of a minimum mean square error,
can be that:
wherein, M is the mass of the experimental model or the actual object, a is the acceleration of the experimental model or the actual object, and V is the linear motion speed of the experimental model or the actual object;
a is the dynamic friction force of the experimental model or the actual object, B is the coefficient of the force of the experimental model or the actual object which is in direct proportion to the speed, C is the coefficient of the pneumatic resistance, and the pneumatic resistance is in direct proportion to the square of the speed.
A, B and C can be obtained by using the linear equation system (only three unknowns A, B and C).
Step 423 using a ═ mmg mu and CD＝C+μCLThe coefficient of dynamic friction mu and the coefficient of aerodynamic drag C can be calculatedD。
The data processing method in step 411 includes:
and manufacturing a speed-time evolution curve of the experimental model according to the first time interval and all the acquired acceleration values.
In the invention, the collected acceleration and vertical force test data of the model experiment device in the experiment movement process are subjected to proper data processing, so that the combination and simultaneous measurement of the aerodynamic lift and the aerodynamic drag coefficients are realized, and an experiment and test basis is provided for replacing an aerodynamic test by using a dynamic model. The method can be used for testing and evaluating the combination of the aerodynamic lift coefficient and the aerodynamic drag coefficient of the model in a dynamic model experiment, and further obtains the aerodynamic lift and the aerodynamic drag of an actual vehicle or an aircraft at different speeds.
Compared with a wind tunnel test, the dynamic model test in the invention has wider speed test range, larger Reynolds number and approximate wireless flow field space, short test time and low cost; in addition, the dynamic model experiment can complete more running conditions, such as the open line intersection of a high-speed train, the tunnel passing and the tunnel intersection of the train and the like.
The above embodiments are only exemplary embodiments of the present application, and are not intended to limit the present application, and the protection scope of the present application is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present application and such modifications and equivalents should also be considered to be within the scope of the present application.
Claims (6)
1. A method for jointly measuring aerodynamic lift and aerodynamic drag coefficients is characterized by comprising the following steps:
step 100: establishing a model device for a dynamic model experiment;
step 200: arranging a data acquisition module on the model device, weighing the weight of an integral experimental model formed by the model device and the data acquisition module, and recording the measured weight as mm(ii) a The data acquisition module is used for acquiring data at a first time interval delta taMeasuring acceleration values of the experimental model in sequence at a second time interval deltatFSequentially measuring vertical force values of the experimental model;
step 300: completing the experiment of different speed areas of the experimental model on the dynamic model experimental device, and obtaining multiple effective experimental values;
step 400: and sequentially obtaining the aerodynamic lift coefficient and the aerodynamic drag coefficient of the experimental model in the dynamic model experimental process through data processing and calculation based on the plurality of acceleration values and the plurality of vertical force values of the experimental model obtained by the data acquisition module.
2. The method for jointly measuring the aerodynamic lift and the aerodynamic drag coefficient as claimed in claim 1, wherein the motion process of each experiment of the experimental model in the dynamic model experimental apparatus comprises an acceleration section, an experimental section and a deceleration section, and the experimental model sequentially passes through the acceleration section, the experimental section and the deceleration section from zero speed until stopping; wherein the content of the first and second substances,
the acceleration value comprises the experimental values of the acceleration section, the experimental section and the deceleration section, which are sequentially recorded as ai(i＝1,K)，ai(i ═ K +1, M) and ai(i＝M+1,N)；
The vertical force value is the experimental value of the experimental section and is marked as Fi(i＝1,M′)；
And K represents the end point of the experimental model reaching the acceleration section, M represents the end point of the experimental model reaching the test section and represents the start of deceleration of the experimental model, and N represents the end point static state of the experimental model after the operation of the deceleration section.
3. The method of claim 2, wherein the aerodynamic lift coefficient and the aerodynamic drag coefficient are measured in combination,
in the acceleration section, the speed of the test model is increased monotonously;
in the experimental section, the speed of the experimental model slowly and uniformly decreases;
during the deceleration phase, the speed of the test model drops sharply.
4. The method for the combined measurement of the aerodynamic lift coefficient and the aerodynamic drag coefficient according to claim 1 or 2, wherein the method for calculating the aerodynamic lift coefficient comprises the following steps:
step 411 according to the firstCalculating the speed value of the experimental model in the experimental section by the time interval and all the obtained acceleration values, and recording as Vi(i＝K+1,M)；
Step 412, based on the relation of aerodynamic lift: fL＝CLV2Obtaining the aerodynamic lift coefficient CL＝FL/V2；
According to the principle that in aerodynamics, the aerodynamic lift force is in direct proportion to the square of the speed of an experimental model, the coefficient of the aerodynamic lift force is obtained
Conversion to dynamic model test, aerodynamic lift coefficient
Wherein, FLThe aerodynamic lift of the experimental model in the dynamic model test process is represented, and V is the speed of the model; fiThe pneumatic lift value is obtained by experimental measurement; j takes the value of the experimental model in all or one time range of the experimental section;
when Δ t is reachedFAnd Δ taWhen the sampling time is the same frequency and synchronous, then delta tF＝Δta；
In the above experimental tests CLThe discrete value expression of (a) is simplified as:
obtaining the aerodynamic lift coefficient:
step 413, calculating an average value according to a plurality of aerodynamic lift coefficients obtained by a plurality of experiments to obtain a target aerodynamic lift coefficient CL。
5. The method for jointly measuring aerodynamic lift and drag coefficients according to claim 1 or 2, wherein the method for calculating aerodynamic drag coefficients comprises:
step 421, calculating the average speed value V of the experimental model in the experimental sectionT,KAnd average acceleration value aT,K(ii) a Wherein K is 1 to N0And N is0The number of experiments is more than or equal to 3;
step 422, utilizing the Davis equation Ma in aerodynamics as A + BV + CV2；
To obtain a weight mmThe davis equation of the experimental model
And using the Davis equations of the experimental model and (V)T,K,aT,K) Constant values A, B and C can be obtained respectively by numerical fitting of the minimum mean square error;
step 423 using a ═ mmg mu and CD＝C+μCLThe coefficient of dynamic friction mu and the coefficient of aerodynamic drag C can be calculatedD；
Wherein, M is the mass of the experimental model or the actual object, a is the acceleration of the experimental model or the actual object, and V is the linear motion speed of the experimental model or the actual object;
a is the dynamic friction force of the experimental model or the actual object, B is the coefficient of the force of the experimental model or the actual object which is in direct proportion to the speed, C is the coefficient of the pneumatic resistance, and the pneumatic resistance is in direct proportion to the square of the speed.
6. The method of claim 4, wherein the data processing in step 411 comprises:
and manufacturing a speed-time evolution curve of the experimental model according to the first time interval and all the acquired acceleration values.
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