Experimental And Numerical Simulation Research On Micro-scale Atomization Chip

Pulmonary inhalation administration is to deliver drugs into the lungs through a specific device to treat respiratory diseases or other targeted sites after being absorbed into the blood circulation through the lungs.As a key factor affecting drug delivery and lung deposition,inhalation devices have high research value and necessity.As a relatively newly developed spray inhaler,Respimat^?Soft Mist^TM is different from traditional nebulizers,metered-dose inhalers and dry powder inhalers.This new type of inhaler can produce longer duration,relatively slow and fine aerosols with high particle content.If some original properties of the aerosol produced by the device and the effect of the geometric parameters of the device on the atomization can be obtained,it will provide greater help for the generic device development,improvement and optimization of the spray inhalation device.In this paper,through building an experimental platform for high-speed laser imaging and proposing effective processing methods,as well as designing an experimental set-up for laser particle size analyzers,key parameters such as geometry pattern and particle size distribution of Respimat^?Soft Mist^TM can be measured.The device has also been verified the repeated uniformity of the spray and the high rate of fine particles.In this paper,through computational fluid dynamics simulation,using the volume of fluid function method,coupled with the SST k-ωturbulence model,a numerical research was carried out on the effect of the key geometric parameters of the device on atomization.The relationship of some parameters on the spray velocity distribution and geometry pattern was gained,as well as the influence on the liquid sheet disturbance formed through the convergent jet.The geometry pattern will be directly affected through the flow velocity,and their changing trends are opposite.The fluctuation and breakage of the liquid sheet at the micro-scale are not affected.It is affected through the impact angle of the jet,the length of the pre-jet,the diameter of the jet,the ambient gas and pressure.For the development of new types of chips in the future,it is necessary to combine the relationship between speed and geometry pattern,as well as the relationship between liquid atomization,fragmentation and chip geometric parameters,so as to design atomization chips that can produce the most suitable aerosol for patient inhalation.