A feasibility study of passive ventilation via origami-driven stack effect

TL;DR

This work addresses energy-efficient, passive ventilation by enabling controllable buoyancy-driven airflow through a retrofitted origami-driven stack extension. It combines Kresling origami cells with a base-actuated mechanism to adjust the effective stack height $H$ and vent area $A$, and it evaluates performance using 3D CFD and analytical stack-effect modeling, exploring parameters such as the unit-cell side count $n$ and aspect ratio $\alpha$. The results indicate about a $25\%$ increase in ventilation for each doubling of the origami stack height, and up to roughly a $3\times$ tunability by varying $\alpha$, with practical guidance that at least six panels are needed for efficient enhancement. These findings support the potential of adaptive, energy-efficient ventilation for off-grid and extreme environments, while highlighting the need for experimental validation to confirm real-world feasibility.

Abstract

This study introduces an innovative ventilation system, which leverages an origami-inspired structure to improve and regulate natural airflow driven by the stack effect, with applications in underground mines and buildings. The proposed system retrofits chimneys and/or exhaust risers with expandable origami units that dynamically modulate their geometric features (height and vent area) to control buoyancy-driven ventilation independent of external wind or solar conditions. The efficacy of the proposed concept is evaluated using a three-dimensional computational model that focuses on how the geometric design of the deployable stack and varying atmospheric conditions affect the volumetric airflow through the stack in both its fully expanded and contracted states. The results show that the ventilation rate increases by up to 25\% with each doubling of the height of the origami stack. % These findings highlight the potential of leveraging origami-inspired structures for adaptable and controllable energy-efficient ventilation, which is particularly beneficial in energy-intensive applications and/or remote, off-grid locations.

Figures (15)

• Figure 1: Kresling origami in (a) expanded state and (b) contracted state, with the corresponding top view of the (c) expanded state and (d) contracted state.
• Figure 1: Velocity contours of all cases in expanded state.
• Figure 2: Proposed concept for enhancing and managing passive ventilation through (a) expanding and (b) contracting a retrofitted origami duct. Subscripts 'e' and 'c' indicate expanded and contracted states of origami, respectively, with subscript 'o' referring to original system prior to retrofitting origami.
• Figure 2: Velocity contours of all cases in contracted state.
• Figure 3: Illustration of actuation mechanism in our proposed concept: (a) Components of a single origami unit cell, (b) compression of a unit upon rotation, and (c) compression of a stack of origami units