A Mars dust storm simulator and a Mars dust storm experimental method thereof

Abstract

The present invention discloses a Mars dust storm simulator and a Mars dust storm experimental method thereof, belonging to the technical field of Mars atmosphere simulation experiments, comprising a mechanical motion experimental platform and a closed container installed on the mechanical motion experimental platform, wherein the motion modes of the mechanical motion experimental platform include horizontal reciprocating oscillation, vertical reciprocating oscillation and variable speed rotation, and the closed container is sealed and filled with mineral particles and carbon dioxide gas under low pressure conditions, and the closed container is connected to a monitoring device, and dust storms of different intensities are simulated in the closed container by controlling different motion modes of the mechanical motion experimental platform, and experimental data of the dust storm in the closed container are obtained by the monitoring device. The present invention drives the closed container to complete different motion modes through the mechanical motion experimental platform, simulates dust storms of different intensities in the closed container, and realizes the simulation of its internal environment by the overall motion of the closed container, thereby avoiding the problem of poor precision of stirring action and wind source blowing, and improving the precision of Mars dust storm simulation.

Description

Technical Field

[0001] The present invention relates to the technical field of Martian atmosphere simulation experiments, and in particular to a Martian dust storm simulator and a Martian dust storm experiment method thereof. Background Art

[0002] There are huge differences between the atmospheric environment and surface materials of Mars and those of the Earth: for example, the Martian atmosphere, which is mainly composed of carbon dioxide, is thin and dry (containing 95.5% CO2, 2.7% N2, 1.6% Ar and other trace gases, and the average surface pressure is only 700Pa), and strong ultraviolet / cosmic ray radiation causes the Martian atmosphere to have a high degree of ionization. At the same time, Mars is also a planet with global dust storms, and the impact of dust storms on Mars cannot be ignored. Research on dust storms helps to deepen the understanding of the Martian atmospheric electric field (generation mechanism, electric field characteristics, evolution laws), atmospheric discharge phenomena, and the strong interaction between the Martian atmosphere and surface materials caused by discharge. However, there is currently no actual measurement data and simulation experimental data on Mars, which limits the in-depth study of the above scientific issues.

[0003] In the absence of in-situ detection data from the Martian surface atmospheric electric field measuring instrument, laboratory simulation, especially laboratory simulation close to the Martian environment, is the only feasible and effective way to solve the above scientific problems. In-depth research on the generation mechanism, intensity characteristics, evolution characteristics of the atmospheric electric field of Martian dust storms, and the relationship between the electric field characteristics and wind speed changes, air pressure, and dust mineral particle types in dust storms will increase people's in-depth understanding of the Martian atmospheric environment and environmental evolution.

[0004] The Chinese patent with the authorization announcement number CN107290002B discloses a Mars dust storm simulation experimental device and experimental method. The experimental device includes a closed container and a photoelectric measuring device. A rotating part is provided in the closed container, and a driving part is provided outside the closed container. The transmission rod of the driving part passes through the closed container and is connected to the rotating part; the photoelectric measuring device includes a fiber optic probe and a photomultiplier tube connected to the fiber optic probe. The fiber optic probe is installed on the quartz window of the closed container, and the photomultiplier tube is located outside the closed container. This scheme simulates the sandstorm on the surface of Mars by rotating the rotating part in the closed container. However, the high-intensity collision between the rotating part and the mineral particles interferes with the authenticity of the dust storm simulation, which brings technical difficulties to the accurate realization of the Mars dust storm simulation. Moreover, the simulation can only be performed by rotation, and the simulation method is single.

[0005] For another example, a Chinese patent with application publication number CN114104347A discloses a vacuum container device for simulating the low-pressure dust storm environment on Mars, which includes a cylinder and a tank car. The bottom of the cylinder is fixed on two saddles, one side of the cylinder is hingedly connected to the gate, and two guide rails are arranged at the bottom of the cylinder. The tank car is a frame structure, and two tracks are arranged on the tank car. The two tracks are connected to the two guide rails in the cylinder. A plurality of flange interfaces are provided on the cylinder, which are connected to the vacuum system, the measurement and control system, the ejector and / or the sand and dust system through the flange interface. This scheme simulates the sand and dust environment on the surface of Mars by using the wind source arranged in the wind tunnel to drive the movement of Martian dust, simulate the atmospheric pressure, density, temperature and the Martian atmosphere and dust storm flow field environment of Mars. However, different environmental changes can only be simulated by changing the size of the wind source. The degree of change from near to far at the wind source is large, resulting in poor accuracy of the final simulation. Summary of the invention

[0006] The purpose of the present invention is to provide a Martian dust storm simulator and a Martian dust storm experimental method thereof to solve the problems existing in the above-mentioned prior art. Mineral particles and carbon dioxide gas are filled in a closed container to simulate the low-pressure environment of Mars, and the closed container is driven by a mechanical motion experimental platform to complete different motion modes to simulate dust storms of different intensities in the closed container. The internal environment of the closed container can be simulated by the overall movement of the closed container, thereby avoiding the problem of poor accuracy caused by stirring action and wind blowing, and improving the accuracy of Martian dust storm simulation.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a Mars dust storm simulator, comprising a mechanical motion experimental platform and a closed container installed on the mechanical motion experimental platform, wherein the motion modes of the mechanical motion experimental platform include horizontal reciprocating oscillation, vertical reciprocating oscillation and variable speed rotation, the closed container is sealed and filled with mineral particles and carbon dioxide gas under low pressure conditions, the closed container is connected to a monitoring device, and dust storms of different intensities are simulated in the closed container by controlling different motion modes of the mechanical motion experimental platform, and experimental data of the dust storm in the closed container is obtained through the monitoring device.

[0009] Preferably, the monitoring device comprises a fiber optic spectrometer, and the fiber optic spectrometer is used to measure the spectrum of the dust storm discharge in the closed container.

[0010] Preferably, the monitoring device comprises a wireless micro camera, which is used to monitor the image of the mineral particles in the closed container, analyze the movement speed of the mineral particles, and the distribution of the mineral particles during the oscillation process.

[0011] Preferably, the monitoring device comprises an atmospheric electric field / conductivity measuring instrument, which is used for online measurement of the electric field strength and atmospheric conductivity in the closed container.

[0012] Preferably, the atmospheric electric field / conductivity measuring instrument includes a spherical electrode for coupling with the Martian atmosphere to generate an induced electromotive force, an insulating bracket for mounting the spherical electrode, and a grounding plate as a reference electrode. The potential difference between the induced electromotive force generated by the spherical electrode and the grounding plate is used as an analog sensing signal. The analog sensing signal is adjusted by an analog signal conditioning circuit to obtain a first analog sensing signal, and the first analog sensing signal is converted into a digital signal by a digital circuit.

[0013] Preferably, three identical spherical electrodes are respectively installed in the X-axis direction, the Y-axis direction and the Z-axis direction through the insulating bracket to simultaneously detect three induced electromotive forces generated by the dust storm in three-dimensional directions.

[0014] Preferably, the sealed container is a quartz glass tube.

[0015] The present invention also provides a Mars dust storm experimental method, using the Mars dust storm simulator described above, comprising the following contents:

[0016] Filling a sealed container with simulated Martian atmosphere and representative Martian minerals, and setting it to Martian low pressure conditions, to form a sealed container containing Martian atmospheric components, Martian atmospheric pressure, and a certain amount of Martian minerals;

[0017] Starting a mechanical motion experimental platform, the mechanical motion experimental platform drives the closed container to perform horizontal reciprocating oscillation, vertical reciprocating oscillation or variable speed rotation, so as to form dust storms of different intensities in the closed container;

[0018] Monitoring the experimental data of the dust storm in the closed container by a monitoring device, and recording and analyzing the experimental data;

[0019] Turn off the mechanical motion experimental platform.

[0020] Preferably, the spectrum of the dust storm discharge in the closed container is measured, the image of the mineral particles in the closed container is monitored, the movement speed of the mineral particles and the distribution of the mineral particles during the oscillation process are analyzed, the electric field strength and the atmospheric conductivity in the closed container are measured online, and the experimental data are obtained in the above manner. The measured experimental data are summarized to analyze the atmospheric electric field characteristics and atmospheric discharge forms when a dust storm occurs.

[0021] Preferably, after closing the mechanical motion experimental platform, the samples in the sealed container are taken out for offline analysis, the alteration products are identified and the yield of the alteration products is analyzed, and the mineral alteration caused by the strong interaction between the discharge and the Martian surface material is analyzed.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] (1) The present invention simulates the low-pressure environment of Mars by filling a closed container with mineral particles and carbon dioxide gas, and drives the closed container to complete different motion modes through a mechanical motion experimental platform to simulate dust storms of different intensities in the closed container. The internal environment of the closed container can be simulated by the overall motion of the closed container, thereby avoiding the problem of poor accuracy caused by stirring action and wind source blowing, and improving the accuracy of the simulation of the Martian dust storm.

[0024] (2) The monitoring device of the present invention includes a fiber optic spectrometer, a wireless micro camera and an atmospheric electric field / conductivity measuring instrument. The fiber optic spectrometer can be used to measure the spectrum of dust storm discharge in a closed container, the wireless micro camera can be used to monitor the image of mineral particles in the closed container, the movement speed of mineral particles and the distribution of mineral particles during the oscillation process can be analyzed, and the atmospheric electric field / conductivity measuring instrument can be used to measure the electric field strength and atmospheric conductivity in the closed container online. By summarizing and analyzing the experimental data obtained in the above manner, the atmospheric electric field characteristics and atmospheric discharge forms when a dust storm occurs can be obtained;

[0025] (3) After closing the mechanical motion experimental platform, the present invention takes out the samples in the sealed container for offline analysis, which can identify the alteration products and analyze the yield of the alteration products, and analyze the mineral alteration caused by the strong interaction between the discharge and the Martian surface material;

[0026] (4) The spherical electrode of the atmospheric electric field / conductivity measuring instrument of the present invention is a monopole sensor, which works more stably under Martian dust storm conditions. At the same time, after the analog sensing signal is converted into a digital signal, the digital signal has a stronger anti-interference ability, thereby realizing the measurement of the Martian atmospheric electric field under Martian dust storm conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a schematic diagram of the overall structure of the Mars dust storm simulator of the present invention;

[0029] Figure 2 This is a schematic diagram of the atmospheric electric field / conductivity measuring instrument of the present invention;

[0030] Figure 3 for Figure 2 Detailed structural diagram;

[0031] Figure 4 Schematic diagram of the equivalent circuit structure of the spherical electrode coupled with the Martian atmosphere of the present invention;

[0032] Figure 5 This is an equivalent circuit simulation diagram of the coupling between the spherical electrode of the present invention and the Martian atmosphere;

[0033] Figure 6 The resistor R1 of the present invention is 10 10 Ohm-hour atmospheric electric field / conductivity measuring instrument measurement result diagram;

[0034] Figure 7 The resistor R1 of the present invention is 10 10 The seven-and-a-half-digit ohm meter is used to measure the result of the multimeter.

[0035] Figure 8 The resistor R1 of the present invention is 10 12 Ohm-hour atmospheric electric field / conductivity measuring instrument measurement result diagram;

[0036] Fig. 9 The resistor R1 of the present invention is 10 12 The seven-and-a-half-digit ohm meter is used to measure the result of the multimeter.

[0037] Among them, 1. Sealed container; 2. Wireless micro camera; 3. Fiber optic spectrometer; 4. Atmospheric electric field / conductivity measuring instrument; 41. Spherical electrode; 412. Analog signal conditioning circuit; 413. Digital circuit; 42. Insulating bracket; 43. Grounding plate; 44. First voltage follower; 45. Second voltage follower; 46. Inverting amplifier circuit; 47. Analog-to-digital conversion module; 48. Field programmable logic gate array; 49. Communication module; 5. Mechanical motion experimental platform; 6. Carbon dioxide gas; 7. Mineral particles. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The purpose of the present invention is to provide a Martian dust storm simulator and a Martian dust storm experimental method thereof to solve the problems existing in the prior art. By filling a closed container with mineral particles and carbon dioxide gas to simulate the low-pressure environment of Mars, the closed container is driven by a mechanical motion experimental platform to complete different motion modes to simulate dust storms of different intensities in the closed container. The internal environment of the closed container can be simulated by the overall movement of the closed container, thereby avoiding the problem of poor accuracy caused by stirring action and wind blowing, and improving the accuracy of the Martian dust storm simulation.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 1As shown, the present invention provides a Mars dust storm simulator, including a mechanical motion experimental platform 5 and a closed container 1 installed on the mechanical motion experimental platform 5. The mechanical motion experimental platform 5 can adopt an existing experimental platform, and has multiple motion modes, including horizontal reciprocating oscillation, vertical reciprocating oscillation and variable speed rotation. It is controlled by a control system, and different motion modes of the mechanical motion experimental platform 5 can be obtained according to needs. The sealed container 1 can be made of steel or glass material and has a closable opening. The shape can be round, square, etc. Before the experiment, mineral particles 7 and carbon dioxide gas 6 are filled into the sealed container 1, and after the carbon dioxide gas 6 is filled, the low pressure condition in the sealed container 1 is maintained (in line with the Martian pressure, 700Pa), the carbon dioxide gas 6 is used to simulate the Martian atmosphere, and the mineral particles 7 are used to simulate the Martian dust (the mineral particles 7 select representative mineral components on the surface of Mars, such as feldspar, olivine, pyroxene, quartz, sulfate, etc., and are ground to a certain particle size for mixing), and after the sealed container 1 drives the carbon dioxide gas 6 and mineral particles 7 inside it to move, the Martian dust storm is simulated. By controlling the different movement modes of the mechanical motion experimental platform 5, dust storms of different intensities can be simulated in the sealed container 1. The sealed container 1 is also connected to a monitoring device, which moves with the sealed container 1 under the action of the mechanical motion experimental platform 5, and the experimental data of the dust storm in the sealed container 1 can be obtained through the monitoring device. In summary, typical Martian mineral particles 7 and Martian atmosphere (carbon dioxide gas 6) are sealed in the sealed container 1, that is, the sealed container 1 is already in the Martian environment. Therefore, the sealed container 1 is driven to move by the mechanical motion experimental platform 5, and the form and intensity of the Martian dust storm can be accurately simulated through different motion modes and intensities. However, the existing method of using a stirring device to realize a dust storm has a single vibration form, and the rotating motor bearing is difficult to seal with the sealed container 1. The high-intensity collision between the metal rotating rod, the rotating head and the mineral particles 7 interferes with the authenticity of the dust storm simulation, and brings technical difficulties to the accurate realization of the Martian dust storm simulation. Therefore, the present invention fills the mineral particles 7 and the carbon dioxide gas 6 in the sealed container 1 to simulate the low-pressure environment of Mars, and drives the sealed container 1 to complete different motion modes through the mechanical motion experimental platform 5 to simulate dust storms of different intensities in the sealed container 1. The closed container 1 can be used to simulate its internal environment by the overall movement, avoiding the poor accuracy caused by the stirring action and the blowing of the wind source used in the existing technology to simulate the Martian dust storm, and improving the accuracy of the Martian dust storm simulation.

[0042] Using mineral particles containing volatile elements 7 as the starting agent, the interaction mechanism of atmospheric discharge and volatile elements and mineral chemical alteration under simulated Martian conditions can be studied, where the volatile elements include chlorides, chlorine oxides, bromides, etc.

[0043] The monitoring device may include a fiber optic spectrometer 3, which is used to measure the spectrum of the dust storm discharge in the closed container 1. For example, a fiber optic spectrometer 3 with a wavelength range of 200-1100nm is used. When conducting a dust storm experiment, a spectrometer can be arbitrarily selected within the above wavelength range, that is, any spectrometer with a wavelength range of 200-1100nm can complete the measurement of the plasma spectrum characteristics in the dust storm. The fiber optic spectrometer 3 is located outside the closed container 1 and is connected to the closed container 1 through an optical fiber. Since the discharge phenomenon in the dust storm will produce a large number of oxygen-containing free radicals that induce changes in the atmosphere and surface elements of Mars, when conducting a dust storm simulation experiment, the spectral emission lines produced by the free radicals generated by the discharge in the dust storm of the closed container 1 are excited and transmitted to the fiber optic spectrometer 3 through the optical fiber, so as to measure the spectral characteristics of the plasma in the simulated dust storm, identify the type of free radicals in the dust storm according to the plasma spectral characteristics, and thus obtain the evolution law of the free radical-induced Martian atmosphere and surface elements, providing a research basis for further Mars exploration.

[0044] The monitoring device may include a wireless micro camera 2, which is installed on the outer wall of the closed container 1. The wireless micro camera 2 is used to dynamically monitor the movement of mineral particles 7 in the closed container 1 and the adsorption of mineral particles 7 on the inner wall of the closed container 1 after the oscillation stops. By monitoring the image of the mineral particles 7 in the closed container 1, the movement speed of the mineral particles 7 and the distribution of the mineral particles 7 during the oscillation process are analyzed.

[0045] The monitoring device may also include an atmospheric electric field / conductivity measuring instrument 4, which is used to measure the electric field strength and atmospheric conductivity in the sealed container 1 online, and may use an existing known electric field and conductivity measuring device. The atmospheric electric field / conductivity measuring instrument 4 uses high-frequency data acquisition to eliminate electric field changes caused by repeated oscillations and realize the identification of atmospheric electric field discharge forms.

[0046] Further, such as Figure 2As shown, the atmospheric electric field / conductivity measuring instrument 4 may include a spherical electrode 41 for coupling with the Martian atmosphere to generate an induced electromotive force, an insulating bracket 42 for mounting the spherical electrode 41, and a grounding plate 43 as a reference electrode. The material of the spherical electrode 41 may be copper, stainless steel, aluminum, etc., and the radius of the spherical electrode 41 may be 3 cm, 5 cm, etc. The insulating bracket 42 may be installed inside the sealed container 1, the spherical electrode 41 is installed at one end of the insulating bracket 42, and the grounding plate 43 is installed at the bottom of the sealed container 1. The insulating bracket 42 is wrapped with an insulating resin to prevent interference from the Martian atmospheric electric field, and the insulating resin is polytetrafluoroethylene. The insulating bracket 42 can rotate and is height-adjustable. The potential of the grounding plate 43 is 0, and the potential difference between the induced electromotive force generated by the coupling of the spherical electrode 41 and the Martian atmosphere and the grounding plate 43 is used as an analog sensing signal. The analog sensing signal is adjusted by the analog signal conditioning circuit 412 to obtain a first analog sensing signal. The adjustment of the analog sensing signal specifically includes impedance matching, buffering the analog sensing signal, and amplifying the analog sensing signal. The first analog sensing signal is converted into a digital signal by the digital circuit 413. In summary, the spherical electrode 41 installed on the insulating bracket 42 couples the Martian atmosphere to generate an induced electromotive force. There is a potential difference between the induced electromotive force and the grounding plate 43, that is, an analog sensing signal. The analog sensing signal is adjusted by the analog signal conditioning circuit 412 and then converted into a digital signal by the digital circuit 413. The spherical electrode 41 is a unipolar sensor, and its working state is more stable under Martian dust storm conditions. At the same time, after the analog sensing signal is converted into a digital signal, the digital signal has a stronger anti-interference ability, which realizes the measurement of the Martian atmospheric electric field under Martian dust storm conditions.

[0047] like Figure 3 As shown, the analog signal conditioning circuit 412 includes at least two voltage followers, namely, a first voltage follower 44, a second voltage follower 45 and an inverting amplifier circuit 46. Those skilled in the art can flexibly design the number of voltage followers in the analog signal conditioning circuit 412, such as 2, 3, 4, etc., which will not be elaborated here.

[0048] Taking two voltage followers as an example, the following is introduced:

[0049] The first voltage follower 44 is used for the first impedance matching and buffering of the analog sensing signal; amplifying the analog sensing signal to form an amplified analog sensing signal. Specifically, the first voltage follower 44 has the function of buffering the analog sensing signal and can be used as a buffer stage in the analog signal conditioning circuit 412. Secondly, the first voltage follower 44 can perform impedance matching and improve the carrying capacity of the analog sensing signal. The impedance is greater than or equal to 10 12 Ohm. Because the equivalent input resistance of the spherical electrode 41 coupled with the Martian atmosphere is very large, the equivalent input resistance is in the range of 10 13 to 10 15Ohms, must be matched with a suitable impedance. The model of the first voltage follower 44 can be LMC6041.

[0050] The second voltage follower 45 is connected to the first voltage follower 44, and is used for second impedance matching and buffering the first amplified analog sensing signal; amplifying the first amplified analog sensing signal to form a second amplified analog sensing signal. Specifically, the second voltage follower 45 has the function of buffering the first amplified analog sensing signal, and can be used as a buffer stage in the analog signal conditioning circuit 412. Secondly, the second voltage follower 45 can perform impedance matching and improve the carrying capacity of the first amplified analog sensing signal. The impedance is 1.5×10 12 The model of the second voltage follower 45 may be CA3140.

[0051] The inverting amplifier circuit 46 is connected to the second voltage follower 45, and is used to amplify the secondary amplified analog sensing signal and output the first analog sensing signal. Specifically, the model of the inverting amplifier circuit 46 may be AD8421.

[0052] Reference again Figure 3 As shown, the digital circuit 413 includes an analog-to-digital conversion module 47 , a field programmable logic gate array 48 and a communication module 49 .

[0053] The analog-to-digital conversion module 47 is connected to the inverting amplifier circuit 46, and the analog-to-digital conversion module 47 converts the first analog sensing signal into a digital signal. Specifically, the model of the analog-to-digital conversion module 47 may be AD7768.

[0054] The field programmable logic gate array 48 is connected to the analog-to-digital conversion module 47, and the field programmable logic gate array 48 is used to filter the digital signal to form a filtered digital signal. Specifically, the field programmable logic gate array 48 can be set to passband filtering or stopband filtering. The field programmable logic gate array 48 can smooth the digital signal, remove interference noise, purify the digital signal, and improve the accuracy of the digital signal. Passband filtering means that the desired digital signal can be passed. Stopband filtering means preventing unwanted digital signals from passing. The model of the field programmable logic gate array 48 can be the Spartan6 series.

[0055] The communication module 49 is connected to the field programmable logic gate array 48, and the communication module 49 is used to transmit the filtered digital signal. Specifically, the communication module 49 may include a wireless communication submodule or a wired communication submodule. The model of the communication module 49 may be RS422.

[0056] Three identical spherical electrodes 41 are respectively installed in the X-axis direction, the Y-axis direction and the Z-axis direction through the insulating bracket 42 to simultaneously detect the three induced electromotive forces generated by the dust storm in the three-dimensional direction. Specifically, the insulating bracket 42 can be an XYZ orthogonal 3D support rod, and the XYZ orthogonal 3D support rod can simultaneously install three independent spherical electrodes 41. There are three potential differences between the three independent spherical electrodes 41 and the grounding electrode plate 43, that is, the three independent spherical electrodes 41 will generate (detect or couple) three induced electromotive forces.

[0057] The electrical conductivity of the Martian atmosphere is about 1,000 times that of the Earth's atmosphere. The relevant electric field strength can be inferred by directly measuring the potential difference between two points in the simulated Martian atmosphere in a closed container 1.

[0058] The formula is as follows:

[0059]

[0060] The spherical electrode 41 relies on the resistance phenomenon (impedance matching) to estimate the relevant electric field strength, and the spherical electrode 41 is also called a "relaxation probe". Figure 4 As shown, the equivalent circuit of the coupling between the spherical electrode 41 and the Martian atmosphere is a parallel circuit of a resistor R1 and a capacitor C1. Vacton represents the actual value of the Martian atmospheric electric field (the voltage around the spherical electrode 41), and Velec represents the induced electromotive force (the measured value of the voltage around the spherical electrode 41). Where:

[0061]

[0062] C1=4πεr;

[0063] Wherein σ is the conductivity of the Martian atmosphere, ε is the vacuum dielectric constant, and r is the radius of the spherical electrode 41 .

[0064] From the above formula, we can see that the resistance R1 is inversely proportional to the Martian atmospheric conductivity σ and the radius r of the spherical electrode 41. In order to make the resistance R1 as small as possible, this can be achieved by increasing the radius of the spherical electrode 41. Since the Martian atmospheric conductivity σ is relatively small (about 10 -11 S / m), which is only comparable to the conductivity of the Earth's stratosphere atmosphere, resulting in a large value of the equivalent resistance R1 of the coupling between the spherical electrode 41 and the Martian atmosphere (about 10 11 ohm).

[0065] By assigning different values ​​to the resistor R1 and the capacitor C1, the coupling between the spherical electrode 41 and the Martian atmosphere can be simulated when the Martian atmosphere has different conductivities (corresponding to different weather conditions, especially dust storm weather). Therefore, the induced electromotive force sensed by the spherical electrode 41 under different conductivities of the Martian atmosphere can be simulated by inputting different voltage signals to the atmospheric electric field / conductivity measuring instrument 4, and the voltage calibration can be performed by observing and summarizing the magnitude of the induced electromotive force output by the atmospheric electric field / conductivity measuring instrument 4 under different input voltage signals. The different values ​​of the resistor R1 and the capacitor C1 are shown in Table 1:

[0066] Table 1

[0067]

[0068] The simulation software Multisim is used for simulation. The value of Vacton is 10V. The values ​​of resistor R1 and capacitor C1 are shown in Table 1. The change of Velec is shown in Figure 5 As shown, Figure 5 The two signal changes in the figure are the changes in Velec when Vacton is added and when Vacton is stopped. The vertical axis is the Velec voltage and the horizontal axis is time.

[0069] See also Figure 5 After adding Vacton, capacitor C1 will quickly charge to a peak value, then start to discharge through resistor R1, and finally stabilize at a specific value (5V); after stopping adding Vacton, capacitor C1 will reverse charge and then discharge, and Velec will suddenly drop and then rise.

[0070] See also Figures 6 to 9 , Vacton values ​​are 50V, 100V, 150V, 200V, 250V respectively, and the atmospheric electric field / conductivity measuring instrument 4 and the 7.5-digit high-precision digital multimeter (model DMM7510) are used to simultaneously detect R1 to be 10 9 Ohm or 10 12 The horizontal axis is the detection frequency and the vertical axis is the value of Velec.

[0071] Depend on Figures 6 to 9 The changes in Velec can be detected and Figure 5The simulation results are basically consistent. The atmospheric electric field / conductivity measuring instrument 4 is consistent with the Velec voltage waveform measured by the seven-and-a-half-digit high-precision digital multimeter. The amplitude of the Velec voltage waveform change is different when the resistance R1 is different. The larger the resistance R1, the smaller the amplitude of the Velec voltage waveform change, that is, the smaller the Martian atmospheric conductivity. The increase in the Velec voltage amplitude increases with the increase of Vacton. When the distance between the spherical electrode 41 and the grounding plate 43 is known, the electric field value within 10 cm near the spherical electrode 41 can be calculated. Therefore, the voltage of the atmospheric electric field / conductivity measuring instrument 4 can be calibrated according to the Velec voltage rise amplitude. The voltage calibration result of the atmospheric electric field / conductivity measuring instrument 4 is related to the Martian atmospheric conductivity. When the Martian atmospheric conductivity is selected, the voltage calibration of the atmospheric electric field / conductivity measuring instrument 4 can be performed. To conduct outdoor dust storm simulation and electric field measurement experiments in the Earth environment, it is necessary to replace the values ​​of resistor R1 and capacitor C1 in Table 1 with values ​​that conform to the range of Earth's atmospheric conductivity and re-measure the voltage.

[0072] The sealed container 1 may be a quartz glass tube, that is, the wall of the sealed container 1 is transparent, which is convenient for observation during the experiment.

[0073] The present invention also provides a Mars dust storm experimental method, which can apply the Mars dust storm simulator described above, and includes the following contents:

[0074] A sealed container 1 is filled with simulated Martian atmosphere (carbon dioxide gas 6) and Martian representative minerals (mineral particles 7) and is set to Martian low pressure conditions (satisfying 700Pa), thereby forming a sealed container 1 containing Martian atmospheric components, Martian atmospheric pressure and a certain amount of Martian minerals.

[0075] The mechanical motion experimental platform 5 is started, and the closed container 1 is driven by the mechanical motion experimental platform 5 to perform horizontal reciprocating oscillation, vertical reciprocating oscillation or variable speed rotation, so that dust storms of different intensities are formed in the closed container 1.

[0076] The experimental data of the dust storm in the closed container 1 is monitored by a monitoring device, and the experimental data is recorded and analyzed.

[0077] Turn off the mechanical motion experimental platform 5 and the experiment ends.

[0078] During the experiment, the spectrum of the dust storm discharge in the closed container 1 can be measured, the image of the mineral particles 7 in the closed container 1 can be monitored, the movement speed of the mineral particles 7 and the distribution of the mineral particles 7 during the oscillation process can be analyzed, and the electric field strength and atmospheric conductivity in the closed container 1 can be measured online. The experimental data can be obtained in the above manner, and the measured experimental data can be summarized to analyze the atmospheric electric field characteristics and atmospheric discharge forms when the dust storm occurs.

[0079] After closing the mechanical motion experimental platform 5, the samples in the sealed container 1 are taken out for offline analysis to identify the alteration products and analyze the yield of the alteration products, so as to analyze the mineral alteration caused by the strong interaction between the discharge and the Martian surface material.

[0080] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A Mars dust storm simulator, characterized in that: It comprises a mechanical motion experimental platform and a closed container installed on the mechanical motion experimental platform. The motion modes of the mechanical motion experimental platform include horizontal reciprocating oscillation, vertical reciprocating oscillation and variable speed rotation. The closed container is sealed and filled with mineral particles and carbon dioxide gas under low pressure conditions. The closed container is connected to a monitoring device. By controlling the different motion modes of the mechanical motion experimental platform, dust storms of different intensities are simulated in the closed container. The experimental data of the dust storm in the closed container is obtained through the monitoring device. The closed container adopts a quartz glass tube.

2. The Mars dust storm simulator according to claim 1, characterized in that: The monitoring device comprises a fiber optic spectrometer, which is used to measure the spectrum of the dust storm discharge in the closed container.

3. The Mars dust storm simulator according to claim 2, characterized in that: The monitoring device comprises a wireless micro camera, which is used to monitor the images of the mineral particles in the closed container, analyze the movement speed of the mineral particles, and the distribution of the mineral particles during the oscillation process.

4. The Mars dust storm simulator according to any one of claims 1 to 3, characterized in that: The monitoring device comprises an atmospheric electric field / conductivity measuring instrument, which is used for online measurement of the electric field strength and atmospheric conductivity in the closed container.

5. The Mars dust storm simulator according to claim 4, characterized in that: The atmospheric electric field / conductivity measuring instrument includes a spherical electrode for coupling with the Martian atmosphere to generate an induced electromotive force, an insulating bracket for mounting the spherical electrode, and a grounding plate as a reference electrode. The potential difference between the induced electromotive force generated by the spherical electrode and the grounding plate is used as an analog sensing signal. The analog sensing signal is adjusted by an analog signal conditioning circuit to obtain a first analog sensing signal, and the first analog sensing signal is converted into a digital signal by a digital circuit.

6. The Mars dust storm simulator according to claim 5, characterized in that: The three identical spherical electrodes are respectively installed in the X-axis direction, the Y-axis direction and the Z-axis direction through the insulating bracket to simultaneously detect the three induced electromotive forces generated by the dust storm in the three-dimensional directions.

7. A Martian dust storm experimental method, characterized in that: The Mars dust storm simulator according to any one of claims 1 to 6 is used, comprising the following contents: Filling a sealed container with simulated Martian atmosphere and representative Martian minerals, and setting it to Martian low pressure conditions, to form a sealed container containing Martian atmospheric components, Martian atmospheric pressure, and a certain amount of Martian minerals; Starting a mechanical motion experimental platform, the mechanical motion experimental platform drives the closed container to perform horizontal reciprocating oscillation, vertical reciprocating oscillation or variable speed rotation, so as to form dust storms of different intensities in the closed container; Monitoring the experimental data of the dust storm in the closed container by a monitoring device, and recording and analyzing the experimental data; Turn off the mechanical motion experimental platform.

8. The Martian dust storm experimental method according to claim 7, characterized in that: The spectrum of the dust storm discharge in the closed container is measured, the image of the mineral particles in the closed container is monitored, the movement speed of the mineral particles and the distribution of the mineral particles during the oscillation process are analyzed, the electric field strength and the atmospheric conductivity in the closed container are measured online, and the experimental data are obtained in the above manner. The measured experimental data are summarized to analyze the atmospheric electric field characteristics and atmospheric discharge forms when the dust storm occurs.

9. The Martian dust storm experimental method according to claim 7, characterized in that: After closing the mechanical motion experimental platform, the samples in the sealed container are taken out for off-line analysis to identify the alteration products and analyze the yield of the alteration products, and to analyze the mineral alteration caused by the strong interaction between the discharge and the Martian surface material.

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