Parametric design, multiphysics simulation, and experimental validation of a full-scale 3D-Printed gyroid eco-clay biophilic façade for hot-arid climates

Abstract

Façades in hot-arid Gulf cities face compounding challenges of peak solar irradiance exceeding 1,050 Wh/m2 and potable-water scarcity that renders conventional pressurized green-wall irrigation systems economically and technically impractical. This study presents and experimentally validates the design-build lifecycle of a full-scale 3D-printed eco-clay biophilic façade wall grounded in gyroid triply periodic minimal surface (TPMS) geometry, targeting passive multifunctional environmental performance without mechanical infrastructure. A five-stage EnergyPlus Weather (EPW) file -to-geometry-to-performance pipeline – Grasshopper/Ladybug/HoneyBee/Butterfly climate analysis; TPMS parametric design; Rhinoceros 8/Luban clay AM (additive manufacturing) fabrication; EnergyPlus and ANSYS Fluent computational fluid dynamics simulation; and multi-method experimental validation – established site-specific design targets and quantified performance. Experimental validation comprised: (1) outdoor thermocouple surface monitoring over three consecutive summer days (15-min logging) with infrared thermography; (2) five-point anemometer airflow validation at the fabricated prototype; (3) compressive and shear structural testing on fabricated specimens; (4) expanded passive irrigation testing (n = 10, three inlet flow rates, five wall inclinations); and (5) a cradle-to-grave International Organization for Standardization (ISO)14040/14,044 life-cycle assessment. Monte Carlo uncertainty propagation (n = 10,000 simulations) quantified confidence intervals on all key outcomes. Outdoor thermocouple monitoring over three consecutive sunny days yielded a measured mean peak-hour exterior surface temperature reduction of 5.8 ± 0.6 °C (95% confidence interval, CI: [4.6, 7.0] °C) relative to the flat clay reference wall, with a peak reduction 8.7 °C at 14:00 (EnergyPlus simulation-to-measurement agreement: root-mean-square error, RMSE = 1.4 °C, R2 = 0.97). Five-point anemometer validation confirms ANSYS Fluent CFD predictions within ±7.3% (mean error 5.8%; grid convergence index, GCI <0.9%). Structural testing yields single-block compressive strength 1.80 ± 0.12 MPa (3.6 × cladding minimum threshold) and plug-prism joint shear strength 0.42 ± 0.035 MPa (2.3 × threshold). Expanded irrigation testing (n = 10) yielded a Christiansen Uniformity Coefficient (CUC) = 0.83 ± 0.02 (95% CI: [0.81, 0.85]), with feasibility demonstrated over 0–9° inclination range. A full life-cycle assessment (LCA) indicates 34.0 kg CO2e/m2 cradle-to-grave — 12.1 × lower than an equivalent reinforced-concrete (RC) wall (412 kg CO2e/m2). The validated EPW-to-geometry-to-performance pipeline and consumer-accessible Luban Modular Cut fabrication workflow provide a replicable methodology for passive biophilic façade design in any hot-arid context. The passive gravity-fed irrigation system eliminates active irrigation infrastructure, providing a technically validated alternative aligned with UAE National Water Security Strategy 2036 compliance. This study provides, to the authors' knowledge, the first outdoor experimental thermal validation, direct anemometer CFD validation, structural mechanical characterisation, and ISO 14040/14,044-compliant life-cycle assessment for a full-scale ceramic gyroid TPMS façade component under hot-arid conditions, elevating the contribution from prototype simulation to validated engineering prototype research.