Cigarette draw resistance measuring method and device and storage medium

Abstract

The invention discloses a cigarette draw resistance measuring method and device and a storage medium, and belongs to the cross technical field of computational fluid mechanics and tobacco analysis technology, the cigarette draw resistance measuring method comprises the following steps: constructing a cigarette transient aerodynamics system control equation; a cigarette suction experiment is carried out through the suction device, the suction flow is gradually increased from zero until the maximum suction flow set value is reached, then the suction flow is continuously kept for a period of time until the transient actual measurement pressure is stable, and the transient actual measurement pressure corresponding to different suction flows in the whole air suction process is recorded; substituting into a cigarette transient aerodynamic system control equation as a boundary condition, and solving transient flow through a characteristic line method; establishing a function relation expression of the transient actual measurement pressure and the transient flow; and taking the actually measured cigarette suction flow as transient flow, substituting the transient flow into the function relation expression, and calculating to obtain transient actually measured pressure, wherein the transient actually measured pressure is the cigarette suction resistance. The method has the advantages of high test accuracy, short test time and low sample consumption.

Description

Technical Field

[0001] The invention relates to a method for measuring cigarette draw resistance, and belongs to the cross technical field of computational fluid dynamics and tobacco analysis technology. Background Art

[0002] Cigarette draw resistance is an important parameter indicator for controlling the smoking experience of cigarettes. Cigarette draw resistance is defined as the pressure difference on both sides of a cigarette under standard conditions with a puff flow rate of 17.5 ml / s. Accurate and efficient cigarette draw resistance measurement is crucial for cigarette product quality control. Existing cigarette draw resistance measurements are usually measured by standard puffing devices. The national standard ISO 6565 "Standard conditions and measurements for draw resistance and filter pressure drop of tobacco and tobacco products" recommends the use of a device with a constant volume flow rate for draw resistance measurement. However, the existing test methods have the following defects: (1) The existing measurement standard puff flow rate is large, and the cigarette sample will be deformed after measurement, changing the control conditions. The same cigarette cannot be used for multiple tests, which will consume a large number of cigarette samples and cannot be retested or sold, which is easy to cause waste; (2) It requires testers to spend a lot of time on testing; (3) There may be differences between the draw resistance of static tests and the instantaneous draw resistance experienced by actual users. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method for measuring the draw resistance of cigarettes, which has the advantages of high test accuracy, short test time and less sample consumption.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a method for measuring draw resistance of a cigarette, comprising the following steps:

[0006] The control equations of cigarette transient aerodynamic system are constructed based on continuity equation, momentum equation and energy equation;

[0007] Conduct a cigarette smoking experiment using a smoking device, gradually increase the suction flow rate from zero until it reaches the maximum suction flow rate setting value, and then continue to maintain it for a period of time until the transient measured pressure reaches stability, and record the transient measured pressure corresponding to different suction flow rates during the entire suction process;

[0008] Substitute different suction flow rates and transient measured pressures into the control equation of cigarette transient aerodynamic system as boundary conditions, and obtain the transient flow rate by the characteristic line method.

[0009] According to the values ​​of the transient measured pressure and the transient flow rate, a functional relationship expression of the transient measured pressure and the transient flow rate is established;

[0010] Substitute the measured cigarette suction flow rate as the transient flow rate into the functional relationship expression to calculate the transient measured pressure, and the transient measured pressure is the cigarette drawing resistance.

[0011] The continuity equation, momentum equation and energy equation are formula (1), formula (2) and formula (3) respectively.

[0012] (1),

[0013] (2),

[0014] (3),

[0015] Where ρ is the gas density, A is the cross-sectional area of ​​the cigarette, t is the experimental time, Q is the cigarette flow rate, x is the distance along the cigarette axis, p is the cigarette pressure, π is the circumference, D is the cigarette diameter, f is the cigarette friction coefficient, R is the gas constant, γ is the specific heat ratio, and T is the temperature.

[0016] Constructing the control equation of cigarette transient aerodynamic system considering the ideal gas state equation

[0017] (4),

[0018] Where n is the gas change polytropic index; p0 is the pipeline steady-state pressure; ρ0 is the gas steady-state density.

[0019] The maximum suction flow rate setting value is 30%~40% of the standard suction flow rate.

[0020] In the functional relationship expression, the transient flow rate is the independent variable, the transient measured pressure is the dependent variable, and there is a linear function relationship between the independent variable and the dependent variable.

[0021] The measured cigarette puff flow rate ranges from 5 to 20 ml / s.

[0022] Cigarettes include slim cigarettes with a diameter of 17mm and medium cigarettes with a diameter of 20mm.

[0023] The transient flow rate is obtained by the characteristic line method and the calculation results are obtained by Fortran programming.

[0024] In a second aspect, the present invention provides a device for measuring the draw resistance of a base cigarette, comprising:

[0025] A cigarette transient aerodynamic system control equation construction module, which is used to construct the cigarette transient aerodynamic system control equation based on the continuity equation, momentum equation and energy equation;

[0026] The module for acquiring different suction flow rates and transient measured pressures is used to conduct a cigarette smoking experiment through a smoking device, gradually increase the suction flow rate from zero until it reaches the maximum suction flow rate setting value, and then continue to maintain it for a period of time until the transient measured pressure reaches stability, and record the transient measured pressure corresponding to different suction flow rates during the entire suction process;

[0027] The transient flow solving module is used to substitute different suction flow rates and transient measured pressures into the control equation of the cigarette transient aerodynamic system as boundary conditions, and obtain the transient flow rate by the characteristic line method;

[0028] A function relationship expression establishment module is used to establish a function relationship expression of the transient measured pressure and the transient flow according to the values ​​of the transient measured pressure and the transient flow;

[0029] The cigarette draw resistance calculation module is used to substitute the measured cigarette suction flow rate as the transient flow rate into the function relationship expression to calculate the transient measured pressure, and the transient measured pressure is the cigarette draw resistance.

[0030] In a third aspect, the present invention provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the steps of the cigarette draw resistance measuring method.

[0031] Beneficial effects of the present invention: The present invention provides a method for measuring the draw resistance of cigarettes, which is based on a transient aerodynamic model to measure the draw resistance of cigarettes. A small flow rate is used for the puffing experiment, and the cigarette samples after measurement will not be greatly deformed. The same cigarette can be used for multiple tests to maintain control conditions. There is no need to consume a large number of cigarette samples, and secondary tests or sales can be carried out to reduce test waste. The test personnel only need to spend less time on the test. The measured value is the instantaneous draw resistance, which is consistent with the user experience and has high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of a flow chart of a method for measuring draw resistance of cigarettes of the present invention;

[0033] Figure 2 This is a comparison chart of the results obtained by applying the present invention to the measurement of draw resistance of thin cigarettes and the traditional test method;

[0034] Figure 3 This is a comparison chart of the results obtained by applying the present invention to the measurement of the draw resistance of a medium-sized cigarette and the traditional test method;

[0035] Figure 4 This is a graph showing changes in the suction flow rate and pressure as the suction time progresses in the cigarette smoking experiment in step 2 of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the protection scope of the present invention.

[0037] Example 1

[0038] like Figure 1 As shown, the present invention discloses a method for measuring the draw resistance of a cigarette, comprising the following steps:

[0039] Step 1: construct the control equation of the cigarette transient aerodynamic system based on the continuity equation, momentum equation and energy equation;

[0040] Step 2: Perform a cigarette smoking experiment using a smoking device, gradually increase the smoking flow rate from zero until it reaches the maximum smoking flow rate setting value, and then continue to maintain it for a period of time until the transient measured pressure reaches stability, and record the transient measured pressure corresponding to different smoking flow rates during the entire smoking process;

[0041] Step 3, substituting different suction flow rates and transient measured pressures into the control equation of the cigarette transient aerodynamic system as boundary conditions, and obtaining the transient flow rate by the characteristic line method;

[0042] Step 4: establishing a functional relationship expression of the transient measured pressure and the transient flow rate according to the values ​​of the transient measured pressure and the transient flow rate;

[0043] Step 5: Substitute the measured cigarette suction flow rate as the transient flow rate into the functional relationship expression to calculate the transient measured pressure, and the transient measured pressure is the cigarette suction resistance.

[0044] The present invention provides a method for measuring the draw resistance of cigarettes based on a transient aerodynamic model. A small flow rate is used for the puffing experiment. The cigarette sample after measurement will not be greatly deformed, and the same cigarette can be used for multiple tests to maintain control conditions. There is no need to consume a large amount of cigarette samples, and secondary tests or sales can be carried out to reduce test waste. The test personnel only need to spend less time on the test. The measured value is the instantaneous draw resistance, which is consistent with the user experience and has high accuracy.

[0045] Example 2

[0046] like Figure 1 As shown, the present invention discloses a method for measuring cigarette draw resistance based on a transient aerodynamic model, comprising the following steps:

[0047] Step 1: Construct the transient aerodynamic system control equations, including the continuity equation, momentum equation, and energy equation, which are Formula (1), Formula (2), and Formula (3) respectively.

[0048] (1),

[0049] (2),

[0050] (3),

[0051] In the formula, ρ is the gas density, A is the cross-sectional area of ​​the cigarette, t is the experimental time, Q is the cigarette flow rate, x is the distance along the cigarette axis, p is the cigarette pressure, π is the circumference, D is the cigarette diameter, f is the cigarette friction coefficient, R is the gas constant, γ is the specific heat ratio, and T is the temperature. The unknown parameters in the above formula are ρ, Q, p, and T. Consider the ideal gas state equation:

[0052] (4),

[0053] Where n is the gas change polytropic index; p0 is the pipeline steady-state pressure; ρ0 is the gas steady-state density.

[0054] Step 2: Use the small flow suction test pressure sensor to measure data. First, set the maximum suction flow of the suction device to 30% of the standard suction flow (17.5 ml / s), turn on the pressure sensor recording device, turn on the suction device for suction, and gradually increase the suction flow from zero until it reaches the maximum suction flow setting value, and then continue to maintain it for a period of time until the transient measured pressure reaches stability. After reaching stability, turn off the suction device and stop suction, and record the corresponding transient measured pressure at different suction flow rates during the entire suction process. The specific data is as follows: Figure 4 shown.

[0055] Step 3: Substitute the pressure data obtained by the sensor and the transient measured pressure as boundary conditions into the above equations (1) to (4) and use the characteristic line method to solve the pressure near the cigarette.

[0056] Transient flow.

[0057] Step 4: Establish the functional relationship expression between the transient measured pressure and the transient flow rate.

[0058] (5)

[0059] Where p is the transient measured pressure and Q is the transient flow rate.

[0060] Step 5: Obtain the cigarette draw resistance at different flow rates based on the established function expression. Substituting the flow rate in the range of 5-20 ml / s into formula (5), the cigarette draw resistance at a flow rate of 5-20 ml / s can be obtained. This includes the draw resistance at a standard inhalation flow rate of 17.5 ml / s.

[0061] In order to verify and analyze the simulation effect of the cigarette draw resistance determination method based on the transient aerodynamic model of the present invention, the draw resistance of 17mm slim cigarettes at different puff flow rates was tested using the traditional test method, and the functional relationship between transient draw resistance and flow rate was obtained using the new method: p = 102.39*Q-170.42. The comparison results of the two methods are shown in Figure 2. Figure 2 The results show that the new method proposed in the present invention can well obtain the absorption resistance under different flow rates, and the results are highly consistent with those obtained by the traditional test method (R 2 = 0.9981).

[0062] The traditional test method was used to test the draw resistance of a 20mm medium cigarette at different puff flow rates. The new method was used to obtain the functional relationship between transient draw resistance and flow rate: p = 80.277*Q-100.29. The comparison results of the two methods are shown in the figure below. Figure 3 The results show that the new method proposed in the present invention can well obtain the absorption resistance under different flow rates, and the results are highly consistent with those obtained by the traditional test method (R 2 = 0.9967).

[0063] The invention discloses a method for measuring the draw resistance of cigarettes based on a transient aerodynamic model, which combines the actual system to give the initial calculation conditions, and uses Fortran programming to obtain the calculation results. The initial conditions and boundary conditions in the actual system are substituted, and the initial conditions include the test pipe diameter D, the steady-state pressure p0 at both ends, the gas steady-state density ρ0, the pipe friction coefficient f, the gas constant, and the specific heat ratio γ. The boundary conditions include the sensor pressure and flow data in the test, thereby realizing the simulation of transient flow, using a small flow rate for the suction experiment, and the measured cigarette sample will not be greatly deformed. The same cigarette can be used for multiple tests to maintain the control conditions; there is no need to consume a large number of cigarette samples, and secondary tests or sales can be carried out to reduce test waste; only the test personnel need to spend less time for testing; the measured value is the instantaneous draw resistance, which is consistent with the user experience and has high accuracy.

[0064] Example 3

[0065] The present invention discloses a device for measuring the draw resistance of a base cigarette, comprising:

[0066] A cigarette transient aerodynamic system control equation construction module, which is used to construct the cigarette transient aerodynamic system control equation based on the continuity equation, momentum equation and energy equation;

[0067] The module for acquiring different suction flow rates and transient measured pressures is used to conduct a cigarette smoking experiment through a smoking device, gradually increase the suction flow rate from zero until it reaches the maximum suction flow rate setting value, and then continue to maintain it for a period of time until the transient measured pressure reaches stability, and record the transient measured pressure corresponding to different suction flow rates during the entire suction process;

[0068] The transient flow solving module is used to substitute different suction flow rates and transient measured pressures into the control equation of the cigarette transient aerodynamic system as boundary conditions, and obtain the transient flow rate by the characteristic line method;

[0069] A function relationship expression establishment module is used to establish a function relationship expression of the transient measured pressure and the transient flow according to the values ​​of the transient measured pressure and the transient flow;

[0070] The cigarette draw resistance calculation module is used to substitute the measured cigarette suction flow rate as the transient flow rate into the function relationship expression to calculate the transient measured pressure, and the transient measured pressure is the cigarette draw resistance.

[0071] Example 4

[0072] This embodiment introduces a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the method described in Embodiment 1 or 2 are executed.

[0073] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0074] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0075] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0076] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0077] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for measuring draw resistance of cigarettes, characterized in that: The following steps are involved: The control equations of cigarette transient aerodynamic system are constructed based on continuity equation, momentum equation and energy equation; Control the suction device to conduct a cigarette smoking experiment, gradually increase the suction flow rate from zero until it reaches the maximum suction flow rate setting value, and then continue to maintain it for a period of time until the transient measured pressure reaches stability, and record the corresponding transient measured pressure at different suction flow rates during the entire smoking process; Substitute different suction flow rates and transient measured pressures into the control equation of cigarette transient aerodynamic system as boundary conditions, and obtain the transient flow rate by the characteristic line method. According to the values ​​of the transient measured pressure and the transient flow rate, a functional relationship expression of the transient measured pressure and the transient flow rate is established; Substitute the measured cigarette suction flow rate as the transient flow rate into the functional relationship expression to calculate the transient measured pressure, and the transient measured pressure is the cigarette drawing resistance.

2. The method for measuring the draw resistance of a cigarette according to claim 1, characterized in that: The continuity equation, momentum equation and energy equation are formula (1), formula (2) and formula (3) respectively. （1）， （2）， （3）， Where ρ is the gas density, A is the cross-sectional area of ​​the cigarette, t is the experimental time, Q is the cigarette flow rate, x is the distance along the cigarette axis, p is the cigarette pressure, π is the circumference, D is the cigarette diameter, f is the cigarette friction coefficient, R is the gas constant, γ is the specific heat ratio, and T is the temperature.

3. The method for measuring the draw resistance of cigarettes according to claim 2, characterized in that: Constructing the control equation of cigarette transient aerodynamic system considering the ideal gas state equation （4） Where n is the gas change polytropic index; p0 is the pipeline steady-state pressure; ρ0 is the gas steady-state density.

4. The method for measuring the draw resistance of a cigarette according to claim 1, characterized in that: The maximum suction flow rate setting value is 30%~40% of the standard suction flow rate.

5. The method for measuring the draw resistance of a cigarette according to claim 1, characterized in that: In the functional relationship expression, the transient flow rate is the independent variable, the transient measured pressure is the dependent variable, and there is a linear function relationship between the independent variable and the dependent variable.

6. The method for measuring the draw resistance of a cigarette according to claim 1, characterized in that: The measured cigarette puff flow rate ranges from 5 to 20 ml / s.

7. The method for measuring the draw resistance of a cigarette according to claim 1, characterized in that: Cigarettes include slim cigarettes and medium cigarettes.

8. The method for measuring the draw resistance of a cigarette according to claim 1, characterized in that: The transient flow rate is obtained by the characteristic line method and the calculation results are obtained by Fortran programming.

9. A device for measuring the draw resistance of a base cigarette, characterized in that: include; A cigarette transient aerodynamic system control equation construction module, which is used to construct the cigarette transient aerodynamic system control equation based on the continuity equation, momentum equation and energy equation; The module for acquiring different suction flow rates and transient measured pressures is used to conduct a cigarette smoking experiment through a smoking device, gradually increase the suction flow rate from zero until it reaches the maximum suction flow rate setting value, and then continue to maintain it for a period of time until the transient measured pressure reaches stability, and record the transient measured pressure corresponding to different suction flow rates during the entire suction process; The transient flow solving module is used to substitute different suction flow rates and transient measured pressures into the control equation of the cigarette transient aerodynamic system as boundary conditions, and obtain the transient flow rate by the characteristic line method; A function relationship expression establishment module is used to establish a function relationship expression of the transient measured pressure and the transient flow according to the values ​​of the transient measured pressure and the transient flow; The cigarette draw resistance calculation module is used to substitute the measured cigarette suction flow rate as the transient flow rate into the function relationship expression to calculate the transient measured pressure, and the transient measured pressure is the cigarette draw resistance.

10. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the method for measuring the draw resistance of a cigarette according to any one of claims 1 to 8 are implemented.

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