Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to the field of droplet generation in spray nozzles. In particular, the present disclosure relates to Thin Film in Cross Flow (TFCF) nozzle for controlled and precise generation of liquid droplets with varied diameters and velocities suitable for a sprayer drone.

BACKGROUND
[0002] The agricultural sector is undergoing a transformative phase, marked by the integration of cutting-edge technologies such as drones into traditional farming practices. These unmanned aerial vehicles hold the promise of revolutionizing agricultural operations, offering efficient and precisely targeted application of agrochemicals. This precision is essential for safeguarding crop health and optimizing yields. However, the full potential of these systems is hindered by the limitations inherent in existing nozzle technologies.
[0003] Conventional agricultural drones primarily rely on hydraulic and centrifugal nozzles. Hydraulic nozzles demand changes in nozzle types to achieve varying droplet sizes. In contrast, centrifugal nozzles, despite their widespread use, suffer from a critical drawback, that their tangential ejection velocity results in weak droplet penetration. This limitation compromises the precise delivery of agrochemicals, and additionally, the substantial droplet drift developed during spraying undermines the efficiency of the entire spraying process.
[0004] The evident deficiencies in current spray nozzle technologies emphasize the critical requirement for a transformative solution.
[0005] There is, therefore, a need to provide an improved nozzle capable of generating controlled droplets, and that can overcome the drawbacks of the conventional nozzles.

OBJECTS OF THE INVENTION
[0006] An object of the present invention is to provide a thin film in cross flow (TFCF) nozzle that can enhance the effectiveness of agrochemical spraying applications.
[0007] An object of the present invention is to provide a nozzle to achieve precision in controlling the size and velocity of liquid droplets ejected by the nozzle.
[0008] An object of the present invention is to generate droplets with significant velocity to perform spraying without using the rotor induced airflow.
[0009] An object of the present invention is to enhance the capabilities of agricultural drone spraying, making them more efficient, precise, and adaptable to various crop management practices.
[0010] An object of the present invention is to incorporate a nozzle on a drone's robotic arm for directed and precise spraying near the crops.
[0011] An objective of the present invention is to reduce the environmental impact caused by agrochemical droplet drift, by employing a robotic arm for spraying in the vicinity of crops.

SUMMARY
[0012] Aspects of the present disclosure relate to a Thin Film in Cross Flow (TFCF) nozzle for controlled and precise generation of liquid droplets with different diameters and velocities.
[0013] In an aspect, the nozzle includes a liquid outlet to impinge a jet of liquid on a surface disc, such that the liquid is splashed radially outward forming a thin film of liquid. The nozzle further includes a circumferential air nozzle comprising a cavity to form an air jet that impinges the thin film of liquid to form liquid droplets.
[0014] In an aspect, the formation of the liquid droplets occurs by rupturing the thin film of liquid via cross-flow air from the air jet.
[0015] In an aspect, the formation of the liquid droplets with different diameter and velocity is enabled by adjusting a rate of the cross-flow air and a rate of flow of the liquid.
[0016] In an embodiment, the nozzle may include a means for adjusting a distance between the surface disc and a nozzle exit to achieve the minimum film thickness.
[0017] In an embodiment, the surface disc is positioned in a flow path of the liquid ejected from the liquid outlet.
[0018] In an embodiment, a side arm may be configured with the nozzle and the side arm is configured to hold the surface disc.
[0019] In an embodiment, surface disc facilitates interaction between the air jet and the thin film of liquid in a cross-flow manner.
[0020] In an embodiment, the distance between the surface disc and the nozzle exit is adjusted in response to changes in one or more properties of the liquid.
[0021] In another aspect of the present disclosure, an unmanned aerial vehicle including a robotic telescopic arm is configured to adapt the nozzle. The nozzle incorporated in the unmanned aerial vehicle may facilitate the simultaneous passage of liquid and air as inlet to the nozzle. The nozzle ejects liquid droplets in a vertically downward direction following the cross-flow interaction between air and liquid at nozzle exit.
[0022] In an embodiment, droplets are generated at significant velocity, allowing for spraying without the need for rotor-induced airflow.
[0023] In an embodiment, the unmanned aerial vehicle may include a mechanism to adjust a position and a direction of the nozzle, to enable targeted spraying of one or more agrochemicals.
[0024] In an embodiment, a telescopic arm may be utilized to spray near the crops, thereby reducing agrochemical droplet drift and minimizing environmental impact.
[0025] In an embodiment, the unmanned aerial vehicle may include one or more sensors, and one or more feedback mechanisms to enable real-time adjustments of one or more droplet generation parameters based on environmental conditions.
[0026] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0027] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0028] FIG. 1 illustrates a schematic representation of a cross-section of a thin film in cross-flow (TFCF) nozzle, in accordance with embodiments of the present disclosure;
[0029] FIG. 2 illustrates a perspective view of a TFCF nozzle, in accordance with embodiments of the present disclosure;
[0030] FIGs. 3A-3C illustrate droplet formation stages in the TFCF nozzle, in accordance with embodiments of the present disclosure;
[0031] FIG. 4A depicts the visualization of a droplet under observation at an air inlet velocity of 5 m/s, in accordance with embodiments of the present disclosure;
[0032] FIG. 4B depicts the visualization of a droplet under observation at an air inlet velocity of 12 m/s, in accordance with embodiments of the present disclosure;
[0033] FIG. 5 illustrates an exemplary representation of droplet diameter and velocity measurement setup, in accordance with embodiments of the present disclosure;
[0034] FIGs. 6A-6C illustrate a plot depicting droplet diameter distribution for inlet air velocity, m/s, 8.4 m/s and 4.7m/s, respectively, in accordance with embodiments of the present disclosure;
[0035] FIG. 7 illustrates a plot depicting Volume Mean Diameter (VMD) versus inlet air velocity correlation, in accordance with embodiments of the present disclosure;
[0036] FIGs. 8A-8C illustrate a plot depicting droplet velocity distribution for inlet air velocity, m/s, 8.4 m/s and 4.7m/s, respectively, in accordance with embodiments of the present disclosure;
[0037] FIGs. 9A illustrate an exemplary representation of TFCF nozzle mounted on a drone, in accordance with embodiments of the present disclosure.
[0038] FIGs. 9B illustrates an exemplary representation of the spray structure produced by the TFCF nozzle mounted on a flying drone, in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION
[0039] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[0040] Embodiments described herein relate to a Thin Film in Cross Flow (TFCF) nozzle for controlled and precise generation of liquid droplets with different diameters and velocities.
[0041] In an embodiment, the nozzle includes a liquid outlet to impinge a jet of liquid on a surface disc, such that the liquid is splashed radially outward forming a thin film of liquid. The nozzle further includes a circumferential air nozzle comprising a cavity to form an air jet that impinges the radially splashed liquid to form liquid droplets.
[0042] In an embodiment, the formation of the liquid droplets occurs by rupturing the thin film of liquid via cross-flow air from the air jet.
[0043] In an embodiment, the formation of the liquid droplets with different diameter and velocity is enabled by adjusting the air flow rate and the liquid flow rate.
[0044] In an embodiment, the nozzle may include a means for adjusting a distance between the surface disc and a nozzle exit for attaining minimal film thickness.
[0045] In an embodiment, the surface disc is positioned in a flow path of a liquid ejected from the liquid outlet.
[0046] In an embodiment, a side arm may be configured with the nozzle and the side arm is configured to hold the surface disc.
[0047] In an embodiment, the surface disc facilitate interaction between air and liquid in a cross-flow manner.
[0048] In an embodiment, surface disc facilitates interaction between air jet and thin film of liquid in a cross-flow manner.
[0049] In an embodiment, the distance between the surface disc and the nozzle exit is adjusted in response to changes in one or more properties of the liquid.
[0050] In another aspect of the present disclosure, an unmanned aerial vehicle including a robotic telescopic arm configured to adapt the nozzle is disclosed. The nozzle incorporated in the unmanned aerial vehicle may facilitate simultaneous passage of liquid and air inside the nozzle. It ensures the cross-flow interaction between liquid film and air at the nozzle exit, enabling the ejection of liquid droplets in a vertically downward direction.
[0051] In an embodiment, the unmanned aerial vehicle may include a mechanism to adjust a position and a direction of the nozzle, to enable targeted spraying of one or more agrochemicals.
[0052] In an embodiment, the unmanned aerial vehicle may be equipped with one or more sensors, and one or more feedback mechanisms to enable real-time adjustments of one or more droplet generation parameters based on environmental conditions.
[0053] It is to be further appreciated that while the embodiments of the present disclosure have been explained with respect to nozzle incorporated in an unmanned aerial vehicle for agrochemical and/or water spraying, the nozzle as disclosed in the present invention can be adapted in any of the applications that require accurate droplet generation. The present disclosure can be used as a handheld sprayer, and it can be mounted on tractors or other vehicles for spraying over crops. The present nozzle can also be used in spray-drying processes. All these usages will be covered within the context of the present disclosure.
[0054] The manner in which the proposed TFCF nozzle can be used that enables adjusting air flow rate, liquid flow rate and distance between nozzle exit and disc surface to generate droplets with different diameters and velocity is further explained in detail with respect to FIGs. 1 to FIG. 9B. It is to be noted that drawings of the present subject matter shown here are for illustrative purposes only and are not to be construed as limiting the scope of the subject matter claimed. Further, FIGs may have been explained together, and same reference numerals may have been used to refer to identical components and entities.
[0055] Referring to FIG. 1 to FIG. 2, cross-section of a thin film in cross flow nozzle 100, and a thin film in cross-flow (TFCF) nozzle 200 is disclosed.
[0056] In one embodiment, the TFCF nozzle 200 includes a liquid outlet 102 designed to direct a controlled jet of liquid onto a precisely positioned surface disc 104. This interaction causes the liquid to splash radially outward, forming a delicate and uniform thin film of liquid as denoted by 106. For example, the liquid jet may enter the nozzle 200 via an inlet 108 provided on the nozzle 200 and flow through an internal tubing which may acts as a liquid outlet 102 fixed in a co-axial fixture to form a water jet along the axis of symmetry and the tubing may orient the jet along the central axis of the nozzle. In an example, the internal tubing may be made of silicon.
[0057] In an embodiment, the nozzle 200 may include a circumferential air nozzle 110 that may surround the liquid outlet 102, which includes an air inlet 118 connected to cavity 112 designed to form a precisely directed air jet. This air jet impinges on the radially splashed liquid, rupturing the thin film and resulting in the formation of liquid droplets.
[0058] In an aspect, the proposed nozzle 200 utilizes cross-flow air to rupture the thin film, allowing for the controlled generation of droplets with varying diameters and velocities. The adjustment of air flow rate and liquid flow rate provides a unique and adaptable mechanism for regulating the droplet generation. For instance, when the liquid jet, emitted from the nozzle's outlet, impinges upon a precisely positioned surface disc 104, it spreads radially outward, forming a delicate and uniform liquid film. Concurrently, a circumferential air nozzle 110 generates a carefully directed air jet. This air jet interacts with the liquid film, inducing a cross-flow effect. This cross-flow interaction disrupts the integrity of the liquid film, causing it to rupture into individual droplets. The force and angle of the air jet, coupled with the liquid film's characteristics, determine the size and velocity of the generated droplets.
[0059] For example, in the TFCF nozzle, droplet formation undergoes distinct stages, as shown in FIG 3A-FIG. 3C. Initially, as depicted in Figure 3A, the liquid outlet 102 directs a controlled water jet onto a specialized surface disc 104. This initiation results in the radial development of water flow, a fundamental stage where the liquid spreads radially outward, covering the surface uniformly. Subsequently, the radial water flow evolves into a delicate and uniform thin liquid sheet as shown in FIG. 3B. As the thin liquid sheet reaches optimal conditions, the circumferential air nozzle 110 comes into play, generating a precisely directed air jet as depicted in FIG. 3C. Further, the air interactions with the thin liquid sheet in a cross-flow, cause it to fragment into consistent water droplets.
[0060] Further, both the air and liquid flow rates, disc surface separation from nozzle exit are adjustable independently. By modulating the air flow rate, the intensity of the cross-flow interaction can be controlled. Higher air velocities lead to the production of smaller droplets, while reduced velocities result in larger droplets. Simultaneously, the liquid flow rate and disc surface separation can be adjusted independently to achieve minimum thickness of the liquid film resulting in finer droplets. The capacity to adjust these control parameters separately offers customization of droplet size and velocity to meet specific application needs.
[0061] In one embodiment, the nozzle 200 further incorporates a means for adjusting the distance between the surface disc 104 and a nozzle exit. This adjustment mechanism ensures precise control over the film thickness of the liquid. Further, the surface disc 104 may be positioned in a path of the liquid jet. The surface disc 104 may ensure the uniform formation of the thin liquid film.
[0062] For example, by allowing precise control over the separation between the surface disc 104 and the nozzle exit, the invention achieves adaptability. This adjustment capability is paramount because it controls the film thickness, which directly influences the droplet size and consequently, its velocity.
[0063] In an example, the means for adjusting the distance between the surface disc 104 and the nozzle exit may include a mechanism involving a surface disc 104 and a threaded shaft 114 that controls the separation of the top surface of the surface disc 104 from the nozzle exit. In a non-limiting example, the threaded shaft 114 can be intricately linked to a surface disc 104 equipped with fine threads. These threads function as an adjustment mechanism, enabling precise control over the separation distance between the upper surface of the disc and the nozzle exit.
[0064] In practical application, turning the threaded shaft 114 results in the movement of the surface disc 104. Consequently, adjusting a distance between the surface disc 104 and a nozzle exit may lead to change in the film thickness. Further, the distance between the surface disc 104 and the nozzle exit may be adjusted based on liquid properties to ensure the minimum film thickness. Further, it is to be appreciated that any other alternative mechanisms might be used for adjusting the distance between the surface disc and the nozzle exit. All such adaptations fall within the scope of this application without any limitations.
[0065] In an embodiment, the nozzle 200 incorporates a side arm 116, configured to hold the surface disc 104. The side arm 116 facilitates a unique cross-flow interaction between the air and liquid, enhancing the efficiency of droplet formation. Moreover, the distance between the surface disc 104 and the nozzle exit may be dynamically adjusted in response to changes in liquid properties. This feature may ensure optimal film thickness for liquids of different fluid properties, making the nozzle 200 highly versatile and suitable for various applications. For an example, in large-scale agricultural fields, where wind conditions and temperature can vary significantly, the dynamic adjustment feature ensures that the droplet size and agrochemical spray delivery to crops remain consistent. This adaptability guarantees effective pest control even under changing environmental circumstances, thereby enhancing the overall yield.
[0066] In a non-limiting example, the proposed TFCF nozzle 200 may be integrated into an unmanned aerial vehicle as shown in FIGs. 9A and 9B. For example, the TFCF nozzle 200 may be integrated with the drones via one or more robotic arms. The robotic arms may be configured to adapt the nozzle, allowing for the co-flow of both liquid and air inside the nozzle. The nozzle 200 ejects droplets in a precisely controlled vertically downward direction. Spraying near the crop using a telescopic robotic arm may eliminate drift in the liquid droplets.
[0067] In an embodiment, the unmanned aerial vehicle incorporates one or more mechanisms for adjusting the positioning and direction of the nozzle. These mechanisms may be designed to be responsive to real-time inputs, enabling targeted spraying of one or more agrochemicals. By minimizing wastage and optimizing agrochemicals utilization, this feature enhances the overall efficiency and cost-effectiveness of the spraying process. Further, to ensure the precision, the UAV may be equipped with one or more sensors. The sensors may detect but not limited to environmental conditions such as wind speed, humidity, and temperature, providing real-time data. The feedback mechanisms use this data to make instantaneous adjustments to the robotic arms and droplet generation parameters, such as air flow rate and liquid flow rate guaranteeing accurate and adaptable droplet generation. This real-time adaptability ensures optimal spraying outcomes under diverse environmental circumstances.
[0068] In one embodiment, the liquid jet can be introduced into the nozzle 200 through an inlet 108 utilizing a DC pump (not shown). The DC pump may be configured as a compatible component for the available DC power supply in a typical drone.
[0069] In another embodiment, the liquid jet can also be sourced from other reliable and compatible sources based on the specific needs of their agricultural operations. This adaptability ensures that the TFCF nozzle 200 can seamlessly integrated into a wide range of sprayer drone setups, providing precise and efficient spraying solutions tailored to diverse requirements.
[0070] In an embodiment, the unmanned aerial vehicle may employ a DC air blower (not shown) to introduce air at atmospheric pressure into the nozzle, facilitating the cross-flow effect essential for rupturing the thin liquid film and generating droplets. The DC blower serves as a suitable component for DC power supply available in regular sprayer drones. The use of atmospheric pressure sets this system apart from high-pressure air atomization techniques, ensuring both energy efficiency and simplicity. The invention's flexibility encompasses various air sources, enabling integration of alternatives based on energy efficiency and operational requirements.
[0071] In an embodiment, the unmanned aerial vehicle may also include a control unit (not shown), incorporated within the unmanned aerial vehicle. The control unit may be communicatively coupled to the one or more sensors incorporated within the unmanned aerial vehicle. These sensors may be configured to detect environmental conditions such as wind speed, humidity, and temperature, providing real-time data. The feedback mechanisms use this data to make instantaneous adjustments to the droplet generation parameters, guaranteeing accurate and adaptable droplet generation. This real-time adaptability ensures optimal spraying outcomes under diverse environmental circumstances. The control unit analyzes signals received from the one or more sensors and instructs the control parameters accordingly. In an example, the control unit may be coupled to a memory storing instructions executable by the control unit to perform one or more designated operations.

WORKING EXAMPLE
[0072] In an illustrative example, the droplet size and velocity measurements are performed using Particle/Droplet Image Analysis (PDIA) and Particle Tracking Velocimetry (PTV). In an example, the particle field is lit up using the NdYAg laser of wavelength 532 nm and pulse duration 4ns. The laser is connected to a diffuser that fluorescence at 590 nm, producing a speckle-free background for droplet shadowgraphy. Further, FIG. 5 depicts an example droplet diameter and velocity measurement setup, including the diffuser. The CCD camera with 4MP resolution attached to a Long-Distance Microscope (LDM) is used for imaging the droplets in a spray region of size 3 X 3 mm2 for a resolution of 1.5 µm /pixel. For PTV, the double-pulse laser is fired with an interpulse duration of 5-10 µs. The CCD camera with LDM records a pair of images where particle motion between two images is suitable for velocity estimation. It is to be further appreciated that the provided example of droplet characterization setup serves as an illustration and does not limit the scope of the present application without any limitations, whatsoever.
[0073] Further, the nozzle 200 characterization experiments are performed for different air inlet 118 velocity, 11.6 m/s, 8.4 m/s and 7.4m/s, and water inlet 108 velocity 2.4 m/s. Further may be measured before attaching an airflow pipe to a TFCF nozzle. The air may be injected into the TFCF nozzle 200 using an air blower, and the liquid may be injected using a DC pump. The droplet size reduces with an increase in the airflow velocity for the constant water flow velocity. As can be seen in FIG. 4A, larger droplets are observed for air inlet 118 velocity of 5 m/s, and FIG. 4B depicts reduction in droplet size due to increase in air velocity to 12 m/s.
[0074] Further, the inlet 118 velocity of 11.6 m/s produces droplets with the smallest diameter (as shown in FIG. 6A) compared to the other two air velocities; in this case, the Volume Mean Diameter (VMD) of the droplets is 214 µm. For 8.4m/s droplet VMD is 238 µm (as shown in FIG. 6B), which increases by approximately two times (421 µm) when reduced to 4.7m/s (as shown in FIG. 6C).
[0075] The air inlet 118 velocity correlates with VMD (as shown in FIG. 7) as VMD=A B+C where A = 2.339e+04, B = -3.01 and C = 199.8.
[0076] FIG. 8 shows the droplet velocity distribution for the three values of . The mean of droplet velocity linearly increases with an increase in For m/s, 8.4 m/s and 4.7m/s droplet shows = 7.7m/s, 5.1 m./s and 2.2 m/s respectively. The mean droplet velocity that is proportional to air inlet 118 velocity is expected to improve the droplet penetration during drone spraying. The TFCF nozzle 200 generates droplets in a range that includes both hydraulic and centrifugal nozzles, as shown in table 1. The control over droplet size and the velocity offered by the TFCF nozzle 200 overcomes the limitation of hydraulic and centrifugal nozzles used in drone spraying.

[0077] FIGs. 9A and 9B depict the example TFCF nozzle 200 mounted on an unmanned aerial vehicle for example drone. In an example, the unmanned aerial vehicle incorporates the proposed TFCF nozzle, a DC water pump, and a DC air blower. The example drone shown has a maximum payload capacity of 7.5 kg for four co-axial pairs of rotors. Each rotor is 22 inches in diameter with a diagonal separation of 1m. FIG. 9A shows the TFCF nozzle, marked with a circle, mounted on the bottom side of the bottommost panel of the drone. In an example, the spraying system weighs 800 gm, which is 5% of the drone's weight, and its power consumption is around 200 watts, less than 2.5% of the drone's total power consumption. The depicted triangle in FIG. 9B marks the spray structure produced by the TFCF nozzle 200 without using a downwash of rotors. The nozzle 200 eject droplets in a precisely controlled downward direction, minimizing any significant drifting.
[0078] The conventional sprayer nozzles are typically restricted to mount below the rotor to utilize the induced flow for droplet transport. The proposed TFCF nozzle has overcome this limitation as it does not depend on rotor flow for droplet transport, providing more design flexibility in terms of nozzle mounting.
[0079] In the realm of drone spraying, the issue of drift becomes critical when dealing with droplets smaller than 150 microns. This problem arises mainly from crosswinds and the vortices created by drone movement, significantly affecting droplet trajectory. This drift has detrimental effects on human and animal health, diminishes pollinator populations, and can harm delicate crops. Hydraulic and centrifugal nozzles, due to the elevated release points and reliance solely on rotor downwash for crop transport, produce smaller droplets highly prone to drift. The proposed TFCF nozzle 100, affixed to a telescopic robotic arm, offers a solution. Placing it in close proximity to the intended spraying area mitigates drift concerns. Unlike centrifugal nozzles, which rotate at high speeds (10,000-20,000 RPM) making them challenging to mount on a telescopic arm, and hydraulic nozzles, which lack the necessary droplet momentum for precise crop targeting, the TFCF nozzle addresses these issues effectively.
[0080] Thus, the present disclosure provides a novel cross-flow mechanism and the nozzle 200 where an annular air jet interacts with a thin water film, allowing precise control over droplet size and velocity. Further, the disclosed nozzle may be integrated with drone technology, enhancing the precision of agrochemical applications. By producing droplets tailored to specific needs, the invention minimizes chemical wastage, reduces environmental impact, and optimizes crop protection, leading to increased agricultural sustainability and productivity.

ADVANTAGES OF INVENTION
[0081] The present disclosure provides a TFCF nozzle that allows for control over droplet sizes and droplet penetration velocity.
[0082] The present disclosure provides a nozzle that uses an annular air jet to rupture a thin liquid film which results in the production of controlled and consistent droplets.
[0083] The present disclosure operates at atmospheric pressure, and the nozzle eliminates the need for high-pressure air systems traditionally required for droplet production.
[0084] The present disclosure provides a simple mechanism to control film thickness, enabling adjustment to achieve a minimum film thickness for different fluids.
[0085] The TFCF nozzle generates a downward droplet-laden flow without using rotor's downwash, significantly improving droplet penetration during spraying operations.
[0086] The present disclosure provides a nozzle that minimizes the drift when placed close to the intended spraying area, thereby enhancing the accuracy of the spraying process.
, Claims:1. A thin film in cross flow (TFCF) nozzle (200), comprising:
a liquid outlet (102) to impinge a jet of liquid on a surface disc (104), such that the liquid is splashed radially outward forming a thin film of liquid (106); and
a circumferential air nozzle (110) comprising a cavity (112) to form an air jet that impinges the thin film of liquid (106) to form liquid droplets, wherein the formation of the liquid droplets occurs by rupturing the thin film of liquid (106) via cross-flow air from the air jet.

2. The nozzle (200) as claimed in claim 1, wherein the formation of the liquid droplets with different diameter and velocity is enabled by adjusting a rate of the cross-flow air and a rate of flow of the liquid and film thickness of the liquid.

3. The nozzle (200) as claimed in claim 1, comprising a means for adjusting a distance between the surface disc (104) and a nozzle exit to control the film thickness.

4. The nozzle (200) as claimed in claim 1, wherein the surface disc (104) is positioned in a flow path of the liquid ejected from the liquid outlet (102).

5. The nozzle (200) as claimed in claim 1, comprising a side arm (116) configured with the nozzle (200), wherein the side arm (116) is configured to hold the surface disc (104).

6. The nozzle (200) as claimed in claim 1, wherein the surface disc (104) facilitates interaction between the air jet and the thin film of liquid (106) in a cross-flow manner.

7. The nozzle (200) as claimed in claim 3, wherein the distance between the surface disc (104) and the nozzle exit is adjusted in response to changes in one or more properties of the liquid.

8. An unmanned aerial vehicle, comprising:
a robotic telescopic arm configured to adapt the nozzle (200) as claimed in claim 1, wherein the nozzle (200) facilitates simultaneous passage of liquid and air in the inlet, ensuring a cross-flow interaction between air and thin liquid film at the exit.

9. The vehicle as claimed in claim 8, comprising a mechanism to adjust a position and a direction of the nozzle (200), to enable targeted spraying of one or more agrochemicals near the crop to reduce the drift.

10. The vehicle as claimed in claim 8, comprising one or more sensors, and one or more feedback mechanisms to enable real-time adjustments of one or more droplet generation parameters based on environmental conditions.