Air-based adjustable micro-low-gravity unmanned aerial vehicle experiment platform for multiphase flow research

Abstract

The invention discloses an air-based adjustable micro-low-gravity unmanned aerial vehicle experiment platform for multiphase flow research, and belongs to the field of crossing technologies of aerospace technologies and space science experiments. Comprising a flight structure subsystem which is connected with an intelligent flight control subsystem and used for ensuring that the center-of-gravity position of an aircraft in a full mission profile is stable and is highly matched with a flight control model; the aircraft power subsystem is used for precisely molding a microgravity physical environment and is cooperatively matched with the intelligent flight control subsystem; the intelligent flight control subsystem introduces environment maintenance closed-loop control based on in-cabin inertia feedback, and ensures that the microgravity environment where the experiment load in the unmanned aerial vehicle cabin is located reaches the precision and stability required by scientific experiments; a modular load subsystem includes an external actuator to apply a physical field to the fluid, and a measurement unit to record fluid behavior. According to the unmanned weightlessness aircraft provided by the invention, more than ten times of parabolic flight can be completed in one voyage under the unmanned condition, and the weightlessness level in the period can be adjusted.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of aerospace technology and space science experiments, and specifically relates to an airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research. Background Technology

[0002] With the continuous advancement of manned spaceflight and deep space exploration missions, spacecraft face severe challenges in terms of dynamic characteristics, fluid behavior, and intelligent collaborative control under microgravity environments. To support future major missions such as on-orbit servicing and lunar base construction, it is essential to construct ground-based research facilities capable of accurately simulating the effects of microgravity in space, and to systematically study key scientific issues such as spacecraft motion laws, fluid physics mechanisms, and intelligent collaborative control.

[0003] Microgravity environments are crucial for studying space fluid physics, revealing interfacial behavior and multiphase flow dynamics, and enabling the measurement of physical properties under microgravity conditions. In microgravity, the effects of gravity are significantly reduced, and secondary effects such as surface tension, diffusion-dominated processes, and wettability dominate fluid behavior. This presents spacecraft systems such as propellant management, thermal control, and life support with challenges that are unpredictable on Earth.

[0004] Currently, microgravity experiments mainly rely on space stations, sounding rockets, drop towers, and manned zero-gravity aircraft. Space stations and sounding rockets are expensive and opportunities are scarce; drop towers provide only a few seconds of microgravity time, making it difficult to observe the long-term evolution of fluid systems; while traditional zero-gravity aircraft, such as the US KC-135, the European Space Agency's (ESA) Airbus A310, and the Russian Ilyushin Il-76 MDK, can provide longer durations, but their operating costs are high, risks are significant, and their microgravity levels are low, making it difficult to support complex, high-precision, and high-frequency experimental research. Experiments also require researchers to conduct them in person, and manned operations represent higher aircraft structural standards and personnel training costs. However, multiphase flow experiments or physical property parameter measurement experiments do not require human participation. Using unmanned aerial vehicles (UAVs) instead of manned aircraft can increase control precision while reducing training costs and maximizing experimental safety. In particular, my country's research in the field of microgravity multiphase flow is still in the follower stage, lacking independent models and design principles, which severely restricts the independent research and development of large-scale space fluid systems. Current ground-based simulation methods are limited by time constraints, interference, and parameter range, making it impossible to systematically study the interfacial non-equilibrium evolution, heat and mass transfer mechanisms, and external field control laws of multiphase flow under microgravity. Therefore, there is an urgent need for a dedicated experimental platform that can provide a long-duration, highly stable, and multi-parameter adjustable microgravity environment. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-cost, high-frequency, and specialized airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research. This platform can effectively support the research on the dynamic behavior, control mechanism and model verification of multiphase flow and complex fluid systems under microgravity environment, filling the gap in my country's long-term ground simulation verification capabilities in this field.

[0006] The technical solution adopted in this invention is:

[0007] An experimental platform for multiphase flow research using an airborne tunable micro-low gravity unmanned aerial vehicle, including

[0008] The flight structure subsystem, connected to the intelligent flight control subsystem, is used to ensure that the aircraft's center of gravity is stable and highly matched with the flight control model throughout the mission profile.

[0009] The aircraft propulsion subsystem is used to precisely shape the microgravity physical environment and works in conjunction with the intelligent flight control subsystem.

[0010] The intelligent flight control subsystem introduces an environmental maintenance closed-loop control based on in-cabin inertial feedback, which can adjust in real time and actively counteract disturbances to ensure that the microgravity environment in which the experimental payload is located in the UAV cabin meets the accuracy and stability requirements of scientific experiments.

[0011] The modular load subsystem includes an external actuator that applies a physical field to the fluid and a measurement unit that records the fluid behavior.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The unmanned weightless aircraft proposed in this invention can complete more than ten parabolic flights in one flight without human piloting, and the level of weightlessness during the flight can be adjusted.

[0014] 2. This invention, through the deep integration of unmanned intelligent flight control, high-performance platform reconfiguration, and modular payload services, pioneers a novel paradigm for high-efficiency ground simulation in micro-low gravity environments. The system, centered on highly intelligent autonomous flight control, achieves a leap from traditional trajectory tracking to integrated, precise "trajectory-environment" control. It can autonomously complete high-precision parabolic flight in unmanned mode and actively suppress disturbances, thus providing sustained flight times exceeding 20 seconds with a quality superior to 10. - 2The system achieves internationally advanced levels in accuracy and duration, reaching microgravity environments of g and precisely configurable low-gravity environments exceeding 30 seconds. Technically, the system is based on a mature high-altitude long-endurance UAV platform, undergoing functional reconfiguration for extreme missions. Through structural adaptability enhancement and integrated flight-thrust control, it ensures the platform's safety and reliability under harsh alternating loads while reducing R&D risks and costs, demonstrating significant engineering integration and innovation advantages. Furthermore, the system constructs an open and universal modular experimental ecosystem, providing users with a "plug-and-play" experimental platform through standardized interfaces and integrated service support. This greatly lowers the barrier to entry, making it an efficient, flexible, and reusable public research platform, providing strong innovative support for my country's space science, aerospace technology, and extraterrestrial exploration research.

[0015] 3. The economic and safety advantages of this invention are reflected in the following aspects: Based on a mature high-altitude long-endurance UAV platform, the procurement and modification costs are 1-2 orders of magnitude lower than those of manned weightless aircraft. During operation, there is no need to consider pilot life support systems, and fuel consumption is also lower. Furthermore, the UAV eliminates human error and physiological limitations. The UAV has a higher risk tolerance and can execute flight profiles closer to the aircraft's performance envelope, making it possible to obtain longer microgravity time or higher microgravity mass. Even if the mission fails, there is no risk to personal safety. High microgravity precision and efficiency: The flight control system can perform millisecond-level, ultra-precise automatic control strictly according to the preset optimal trajectory, resulting in smoother and more consistent movements, thus generating a more stable and purer microgravity environment. The deep integration of high-precision flight control in the aviation field with precision measurement technology in space science experiments forms an innovative system with high technological barriers. The operating team is relatively streamlined, and the airspace application process is relatively simplified (especially in specific experimental airspaces), enabling high-frequency operations such as "once a week" or even "once a day," greatly accelerating scientific research iteration. Attached Figure Description

[0016] Figure 1 This is the overall architecture of the system of the present invention;

[0017] Figure 2 This is a schematic diagram of the parabolic flight trajectory and the microgravity phase;

[0018] Figure 3 This is a diagram of a weightless aircraft system;

[0019] Among them: 1. Intelligent flight control subsystem; 2. Aircraft power subsystem. Detailed Implementation

[0020] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0021] This invention relates to an unmanned aerial vehicle (UAV) system and method for simulating microgravity environments within the Earth's atmosphere and specifically for studying the dynamic behavior of multiphase flow and complex fluid systems.

[0022] The core idea of ​​this invention is to construct an integrated "flight-measurement-control" aerial fluid laboratory. Through the systematic reconstruction of a mature high-altitude long-endurance unmanned aerial vehicle platform, it can not only provide a high-quality microgravity environment, but also directly serve cutting-edge scientific research in microgravity fluid physics.

[0023] This invention provides an airborne tunable micro-low gravity unmanned aerial vehicle (UAV) experimental platform for multiphase flow research, comprising:

[0024] 1. Flight structure subsystem, requirements: withstand alternating loads of -2g to 1g, and ensure an aircraft lifespan of more than 10 years.

[0025] The platform is reinforced against low-cycle fatigue damage and alternating loads to ensure it can withstand repeated parabolic maneuvering loads. The UAV mission cabin is designed as an integrated unit, providing optimal installation space and stability for fluid experimental equipment. The flight structure subsystem is the physical carrier and cornerstone of the platform's safety; its overall design is an adaptive redesign for parabolic flight while retaining the original UAV's excellent aerodynamic characteristics for high-altitude, long-endurance flight.

[0026] The specific technical solutions include:

[0027] Airframe structural reinforcement: Based on the intense, periodic alternating loads generated by parabolic flight (typically -1g to 2g, or -2g to 1g cycles), the main load-bearing structures of the UAV, such as the wings and fuselage, underwent finite element re-verification and localized reinforcement design. Emphasis was placed on reinforcing the wing roots, fuselage keel beams, and mission bay docking area, using materials with high specific strength and excellent fatigue resistance to fundamentally ensure the platform's structural integrity and life-cycle safety during aerobatic flight.

[0028] The specific materials are as follows: carbon fiber reinforced resin matrix composite (CFRP) is used for the main fuselage structure, wings, tail, and fairing; titanium alloy Ti-6Al-4V is used for the landing gear, engine pylons, wing spars, and high-temperature components; thermoplastic composite (CF / PEEK) is used for the engine nacelle, internal support brackets, clamps, and integrated structure of the UAV; and ceramic matrix composite (CMC) is used for the hot-end components of the aero-engine, such as the combustion chamber and turbine guide vanes.

[0029] Functional transformation of the mission module: The original mission module space was reimagined and transformed into a large, open, and clean "aerial laboratory." In particular, to meet the needs of hoisting large experimental equipment, docking with on-orbit simulation missions, and deploying fluid experimental systems, a large, fast-opening hatch was installed. This design, while ensuring the overall rigidity and airtightness of the fuselage, greatly improves the accessibility and integration convenience of experimental payloads.

[0030] Active matching of center of gravity and inertia: To cope with changes in the center of gravity caused by fuel consumption and load switching, the microgravity level is altered by adjusting the aircraft's pitch angle and speed when fire is off. The pitch angle is typically set at 40-47°, and the aircraft speed when fire is off is 600-800 km / h.

[0031] The calculation formula is:

[0032]

[0033] in, v is the aircraft's pitch angle at the time of the ceasefire, and v is the aircraft's speed at the time of the ceasefire.

[0034] This ensures that the aircraft's center of gravity remains stable and highly matched with the flight control model throughout the entire mission profile, laying the foundation for precise control by the intelligent flight control subsystem.

[0035] 2. Aircraft power subsystem, requirements: a. Maximum altitude 10,000 meters, cruising altitude 8,000 meters; b. Maximum speed exceeding 600 km / h; c. Fuel supply system operating in weightlessness.

[0036] It possesses high dynamic thrust response capability and works deeply with the intelligent flight control subsystem to provide the power foundation for precise microgravity environments. The aircraft propulsion subsystem is the energy and power core for achieving high-precision parabolic flight, and its function has shifted from providing cruise power to precisely shaping the microgravity physical environment.

[0037] The specific technical solutions include:

[0038] High thrust-to-weight ratio and high-altitude performance: The aircraft employs two high-thrust turbofan engines as its core power plant. This selection ensures that the aircraft still has ample thrust at mission altitudes above 8,000 m, enabling it to accelerate powerfully and complete large pitch angle pull-ups. This provides sufficient kinetic and potential energy for the initial segment of the parabolic trajectory, which is a prerequisite for achieving a high-quality microgravity environment.

[0039] Oil supply and lubrication guarantee: Traditional gravity oil supply methods can no longer meet the oil supply needs of unmanned zero-gravity aircraft. A typical pressure oil supply method should be adopted: squeeze oil tank or forced oil tank.

[0040] High dynamic response and precise control: The engine's full authority digital control system (FADEC) is deeply integrated with the intelligent flight control subsystem. For example, the intelligent flight control subsystem can accurately control the aircraft's pitch angle and fire stop and fire times. The FADEC can receive millisecond-level commands from the flight control system and make rapid and precise stepless adjustments to the engine thrust. This "flight-thrust integration" control capability enables precise counteraction of aerodynamic drag and maintenance of constant airframe speed during microgravity cruise, which is the core execution mechanism for ensuring microgravity levels inside the cabin.

[0041] System-level mission reliability: The dual-engine configuration not only provides necessary thrust redundancy but also constitutes a critical safety barrier for the system. In the extreme case of single engine failure, the platform can still maintain controllable flight and return safely using the other engine. This greatly improves mission availability and overall system reliability, meeting the stringent requirements of high-frequency, repeatable scientific experimental missions.

[0042] 3. Intelligent flight control subsystem, requiring: a. Tracking parabolic trajectory with meter-level accuracy; b. Adjustable microgravity from 0 to 3 / 8g with 10% accuracy. -2 g-level; c. Standardized mechanical, electrical, and information interfaces.

[0043] As the system's "intelligent hub," it innovatively introduces a closed-loop control system for environmental maintenance based on in-cabin inertial feedback. This system not only controls the aircraft to fly a perfect parabolic trajectory but also actively counteracts disturbances through real-time adjustments, ensuring that the microgravity environment in which the experimental payloads are located meets the precision and stability requirements for scientific experiments. The intelligent flight control subsystem is the "intelligent hub" of the entire system, and its goal is to achieve autonomous parabolic flight and microgravity environment maintenance with precision exceeding that of manned pilots.

[0044] The specific technical solution adopts an "online intelligent control system" architecture, which includes:

[0045] High-precision trajectory generation and tracking module: Based on a high-fidelity aircraft dynamics model and real-time flight status (airspeed, altitude, attitude), it calculates the optimal parabolic trajectory online in real time. Through advanced algorithms such as model predictive control, it coordinates the control of elevators, flaps, and engine throttle to achieve meter-level accuracy tracking of the preset nominal trajectory, ensuring the accuracy and consistency of every parabolic flight.

[0046] Microgravity Acceleration Active Control Module: High-precision acceleration sensors are deployed within the mission cabin, and their measurement signals are directly fed into the flight control loop of the intelligent flight control subsystem, forming an additional closed loop focused on environmental maintenance. The intelligent flight control subsystem actively suppresses internal and external disturbances caused by atmospheric turbulence, equipment vibration, etc., by fine-tuning aerodynamic control surfaces and engine thrust, ensuring that the microgravity level experienced by the experimental payloads within the cabin is continuously and stably better than 10.-2 At the gigabyte level, it has achieved a leap from "trajectory tracking" to "environment shaping".

[0047] Cloud-based collaboration and mission management: Utilizing high-speed data links, flight status, control parameters, and payload data are transmitted to ground stations in real time, enabling integrated space-ground monitoring. The ground station has the capability to inject advanced commands and supports large-scale trajectory planning before missions and in-depth data analysis after flight, forming a complete intelligent mission closed loop of "planning-execution-monitoring-learning-optimization".

[0048] Standardized integration interfaces: A unified nacelle slide rail and quick-locking mechanism are set up as mechanical interfaces, as well as standard electrical interfaces. This enables scientific payloads of different disciplines and forms to be quickly installed, switched, and integrated into the system within hours, shortening the mission preparation cycle from "months" to "days".

[0049] An environment maintenance module algorithm is embedded in the computer of the intelligent flight control subsystem (it can dynamically perceive and avoid static / dynamic obstacles, predict risks and autonomously adjust flight strategies to maintain precise hovering and route tracking according to different missions and external environments). A high-precision inertial measurement unit (IMU) is installed in the center of the mission cabin. The high-precision inertial measurement unit is used to accurately measure the three-dimensional attitude of the aircraft and provide high-frequency feedback for the attitude control system; it directly measures the linear acceleration and angular velocity of the aircraft to analyze the motion state and adjust the weightlessness level.

[0050] 4. Modular Payload Subsystem: This invention is not merely an interface, but a reconfigurable fluid experiment platform. Through standardized design, it can rapidly integrate transparent fluid chambers, multiphysics (thermal, electrical, magnetic, acoustic) application devices, and advanced optical measurement systems (such as high-speed cameras, PIVs, and LIFs). This makes this invention a universal research tool, rather than a one-off custom device. The modular payload subsystem is an open experimental ecosystem interface for end users, designed with "plug and play" in mind, completely decoupling the flight platform from rapidly iterating scientific payloads.

[0051] The specific technical solution focuses on three levels:

[0052] Dedicated Experiment Support Module: Addressing common experimental needs, it pre-integrates a range of specialized support hardware, including the following aspects:

[0053] For fluid experiments: an active anti-vibration optical platform is provided to isolate vibrations, and a high frame rate illumination and imaging system is integrated to ensure clear capture of transient interface evolution and flow structure.

[0054] For spacecraft motion simulation experiments: a low-friction air-bearing platform or its installation reference is provided to simulate the resistance-free motion of objects in orbit; at the same time, a docking reference for the robotic arm and a high-speed data acquisition system are preset to capture the entire docking dynamics process.

[0055] Integrated Services and Safety Framework: The modular payload subsystem incorporates centralized power distribution management, precise thermal control, and environmental monitoring units, providing payloads with a stable operating environment comparable to a ground-based laboratory. Simultaneously, through physical constraints and electronic locking mechanisms, it ensures that all payloads remain absolutely fixed and safe under extreme flight conditions, preventing any interference with the flight platform and forming the cornerstone of the entire system's reliable operation.

[0056] The system configuration of this invention:

[0057] Structure and Platform: A structurally reinforced high-altitude long-endurance UAV was selected.

[0058] Powertrain: The FADEC of its engine has been customized to improve throttle response.

[0059] Flight control: An environment maintenance module algorithm is embedded in the flight control computer, and a high-precision inertial measurement unit (IMU) is installed in the center of the mission cabin.

[0060] Load: A custom-designed experimental module. This module includes:

[0061] Transparent chamber: Contains two suspended droplets that can be generated by a micropump.

[0062] External actuator: A pair of miniature electrodes is arranged around the droplet and connected to a high-voltage amplifier. The external actuator is used to apply a physical field to the fluid.

[0063] Measurement Unit: A high-speed camera, equipped with a macro lens and backlight, faces the transparent chamber. The measurement unit is used to record fluid behavior.

[0064] Preparation: Install the experimental module into the UAV mission bay and lock it. Set the flight control parameters; the target microgravity level is 5×10⁻⁶. -3 Based on the experimental requirements for microgravity, during a single voyage, the duration of weightlessness for a single parabola is 20-30 seconds, the maximum track angle is 40-47°, and the number of parabolas is 20-25.

[0065] Flight: The drone takes off autonomously to the designated airspace and begins parabolic flight.

[0066] Experiment execution:

[0067] Once the intelligent flight control subsystem confirms that it has entered the stable microgravity phase (determined by the in-cabin IMU signal), it sends an "experiment start" trigger signal to the modular payload subsystem.

[0068] The high-speed camera begins recording. At a predetermined time, the high-voltage amplifier applies a step voltage according to a preset program.

[0069] The camera captured the entire dynamic process of the two droplets' deformation, migration, and even merging before and after the electric field was applied.

[0070] After a single parabolic flight, the data is automatically saved. The drone prepares for its next flight, and comparative experiments can be conducted by changing the voltage parameters.

[0071] Data Analysis: After recovering the experimental data, the time scale and merging rate of the droplet interface evolution were analyzed through image processing and compared with theoretical models to reveal the regulation law of the electric field on the interface behavior under microgravity.

[0072] This system enables the acquisition of dozens of sets of high-quality experimental data under different parameters in a single task, greatly advancing research on this specific scientific problem. This embodiment demonstrates the immense value of the system of the present invention as a highly efficient and dedicated space-based scientific experimental platform.

[0073] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. An airborne, tunable, low-gravity unmanned aerial vehicle (UAV) experimental platform for multiphase flow research, characterized in that: include The flight structure subsystem, connected to the intelligent flight control subsystem, is used to ensure that the aircraft's center of gravity is stable and highly matched with the flight control model throughout the mission profile. The aircraft propulsion subsystem is used to precisely shape the microgravity physical environment and works in conjunction with the intelligent flight control subsystem. The intelligent flight control subsystem introduces an environmental maintenance closed-loop control based on in-cabin inertial feedback, which can adjust in real time and actively counteract disturbances to ensure that the microgravity environment in which the experimental payload is located in the UAV cabin meets the accuracy and stability requirements of scientific experiments. The modular load subsystem includes an external actuator that applies a physical field to the fluid and a measurement unit that records the fluid behavior.

2. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 1, characterized in that: The drone's mission bay is equipped with a large, quick-opening hatch.

3. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 2, characterized in that: The wing roots, fuselage keel beams, and mission bay docking area of ​​the UAV are made of materials with high specific strength and excellent fatigue resistance.

4. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 1, characterized in that: The flight structure subsystem alters the microgravity level by adjusting the aircraft's pitch angle and speed when fire is stopped. The pitch angle is set to 40-47°, and the aircraft speed when fire is stopped is 600-800 km / h. The calculation formula is: in, v is the aircraft's pitch angle at the time of the ceasefire, and v is the aircraft's speed at the time of the ceasefire.

5. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 1, characterized in that: The core power unit of the aircraft power subsystem is a dual high-thrust turbofan engine. The fuel tank of the aircraft power subsystem is a squeeze-type fuel tank or a forced fuel tank. The engine controller of the aircraft power subsystem is a full authority digital engine controller. The aircraft power subsystem has a dual-engine layout.

6. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 1, characterized in that: The intelligent flight control subsystem includes High-precision trajectory generation and tracking module, microgravity acceleration active control module, cloud collaboration and task management module.

7. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 6, characterized in that: A high-precision acceleration sensor is installed in the mission cabin of the UAV, and its measurement signal is directly introduced into the flight control loop of the intelligent flight control subsystem to form an additional closed loop focused on environmental maintenance. The intelligent flight control subsystem actively suppresses internal and external disturbances caused by atmospheric turbulence, equipment vibration and other factors by fine-tuning the aerodynamic control surfaces and engine thrust, so as to ensure that the microgravity level experienced by the experimental payload in the cabin is continuously and stably better than the order of 10-2 g.

8. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 7, characterized in that: The intelligent flight control subsystem is equipped with a unified mechanical interface and a standard electrical interface.

9. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 1, characterized in that: The modular load subsystem includes an experimental setup module, which contains... Transparent chamber: Contains two suspended droplets that can be generated by a micropump; External actuator: A pair of miniature electrodes is arranged around the droplet and connected to a high-voltage amplifier; Measurement unit: A high-speed camera facing the transparent chamber, equipped with a macro lens and background light.

10. The airborne adjustable micro-low gravity unmanned aerial vehicle experimental platform for multiphase flow research according to claim 9, characterized in that: The experimental method is as follows: Preparation: Install the experimental module into the UAV mission bay and lock it in place. Set the flight control parameters, and set the target microgravity level to 5×10. -3 g. Based on the experimental requirements for micro-low gravity, during a single voyage, the duration of weightlessness for a single parabola is 20-30 seconds, the maximum track angle is 40-47°, and the number of parabolas is 20-25. Flight: The drone autonomously takes off to the designated airspace and begins parabolic flight; Experiment execution: Once the intelligent flight control subsystem confirms that it has entered the stable microgravity phase, it sends an "experiment start" trigger signal to the modular payload subsystem; The high-speed camera begins recording: at a predetermined time point, the high-voltage amplifier applies a step voltage according to a preset program; the camera captures the entire dynamic process of the deformation, migration, and even merging of the two droplets before and after the electric field is applied. After a single parabola is completed, the data is automatically saved, and the drone prepares for the next flight. The voltage parameters can be changed for comparative experiments. Data Analysis: After recovering the experimental data, the time scale and merging rate of the droplet interface evolution were analyzed through image processing and compared with theoretical models to reveal the regulation law of the electric field on the interface behavior under microgravity.

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