ABSTRACT
The present research focuses on analyzing the feasibility of manufacturing complex turbomachinery geometries in a preassembled manner through an uninterrupted additive manufacturing process, absent of internal support structures or post-processing. In the context of the present COVID-19 pandemic, the concept is illustrated by a 3D-printable turbinedriven blower-type medical ventilator, which solely relies on availability of high-pressure oxygen supply and a conventional plastic-printer. Forming a fully pre-assembled turbomachine in its final form, the architecture consists of two concentric parts, a static casing with an embedded hydrostatic bearing surrounding a rotating monolithic shell structure that includes a radial turbine mechanically driving a centrifugal blower, which in turn supplies the oxygen enriched air to the lungs of the patient. Although the component level turbomachinery design of the described architecture relies on well-established guidelines and computational fluid dynamics methods, this approach has the capability to shift the focus of additive manufacturing methods to design for preassembled turbomachinery systems. Upon finalizing the topology, the geometry is manufactured from PETG plastic using a simple tabletop extrusion-based machine and its performance is evaluated in a test facility. The findings of the experimental campaign are reported in terms of flow and loading coefficients and are compared with simulation results. A good agreement is observed between the two data sets, thereby fully corroborating the applied design approach and the viability of additively manufactured pre-assembled turbomachines. Eliminating long and costly processes due to presence of numerous parts, different manufacturing methods, logistics of various subcontractors and complex assembly procedures, the proposed concept has the potential to reduce the cost of a turbomachine to capital equipment depreciation and raw material. Copyright © 2022 by ASME.
ABSTRACT
This work is motivated by the challenges faced during the COVID-19 pandemic. Effective protection from the virus is needed. Masks is one way to protect from the virus. To support the efforots to control the spread of COVID-19 among the population, in this work we present an improved respiratory system consisting of a respiratory mask, air blower and a control system. Our design avoids some of the problems with available masks such as leak of unfiltered air and the irritation caused by these masks. To overcome this problem, the existing respirator is being modified to ensure user can breathe comfortably, no air gap on the side of respirator mask and respirator mask can measure air suction rate. Air blower will increase the air suction rate and sensor will detect the air quality and display it thru the monitor. User can monitor the air index surround them. A prototype is built. Testing of the prototype showed that the system functions as expected and achieves its objectives. On the downside, the prototype is heavier than existing products in the market. Further improvement in the design may lead to an improved version with reduced weight. © 2022 IEEE.