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1. Interactions between urban heat islands and heat waves

   https://doi.org/10.1088/1748-9326/aa9f73  

   Zhao, Lei; Oppenheimer, Michael; Zhu, Qing; Baldwin, Jane W; Ebi, Kristie L; Bou-Zeid, Elie; Guan, Kaiyu; Liu, Xu (March 2018, Environmental Research Letters)
2. Heat purchase agreements could lower barriers to heat pump adoption

   https://doi.org/10.1016/j.apenergy.2021.116489  

   Kircher, Kevin J.; Zhang, K. Max (March 2021, Applied Energy)
3. Inversion for Fire Heat-Release Rate Using Heat Flux Measurements

   https://doi.org/10.1115/1.4046264  

   Kurzawski, Andrew J.; Ezekoye, Ofodike A. (May 2020, Journal of Heat Transfer)

   Abstract In fire hazard calculations, knowledge of the heat-release rate (HRR) of a burning item is imperative. Typically, room-scale calorimetry is conducted to determine the HRRs of common combustible items. However, this process can be prohibitively expensive. In this work, a method is proposed to invert for the HRR of a single item burning in a room using transient heat flux measurements at the walls and ceiling near the item. The primary device used to measure heat flux is the directional flame thermometer (DFT). The utility of the inverse method is explored on both synthetically generated and experimental data using two so-called forward models in the inversion algorithm: fire dynamics simulator (FDS) and the consolidated model of fire and smoke transport (CFAST). The fires in this work have peak HRRs ranging from 200 kW to 400 kW. It was found that FDS outperformed CFAST as a forward model at the expense of increased computational cost and that the error in the inverse reconstruction of a 400 kW steady fire was on par with room-scale oxygen consumption calorimetry. 

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4. Modeling pseudo-turbulent heat flux in gas-solid heat transfer

   https://doi.org/10.1016/j.ces.2023.119371  

   Zhou, Jiazhong; Sun, Bo; Subramaniam, Shankar (January 2024, Chemical Engineering Science)

   Flow past disperse solid particles or bubbles induces fluctuations in carrier fluid velocity, which correlate with temperature fluctuations in non-isothermal flows resulting in the pseudo-turbulent heat flux (PTHF). In the Eulerian-Eulerian (EE) two-fluid (TF) model, the transport of PTHF is shown to be an important contributor to the overall energy budget, and is modeled using a pseudo-turbulent thermal diffusivity (PTTD). The PTHF and PTTD were originally quantified using particle-resolved direct numerical simulation (PR-DNS) data, and correlations were developed over a range of solid volume fraction (0.1 ≤ 𝜀𝑠 ≤ 0.5) and mean slip Reynolds number (1 ≤ 𝑅𝑒𝑚 ≤ 100) for a Prandtl number of 0.7. However, the original PTTD correlation diverges to infinity as the solid volume fraction goes to zero, which is physically unrealistic. This singular behavior is problematic for EE TF simulations at particle material fronts where solid volume fraction values can fall below the lower limit of existing data (𝜀𝑠 =0.1) to zero in the pure carrier phase. In this work, additional PR-DNS data are reported for 𝜀𝑠 < 0.1, and improved correlations are developed for the PTHF and PTTD. The new PTTD correlation is non- singular, and both the PTHF and PTTD decay exponentially to zero as the solid volume fraction approaches zero, which is physically reasonable. This improves prediction of PTHF transport in dilute flow using EE TF heat transfer simulations. 

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5. Persistent urban heat

   https://doi.org/10.1126/sciadv.adj7398  

   Li, Dan; Wang, Linying; Liao, Weilin; Sun, Ting; Katul, Gabriel; Bou-Zeid, Elie; Maronga, Björn (April 2024, Science Advances)

   Urban surface and near-surface air temperatures are known to be often higher than their rural counterparts, a phenomenon now labeled as the urban heat island effect. However, whether the elevated urban temperatures are more persistent than rural temperatures at timescales commensurate to heat waves has not been addressed despite its importance for human health. Combining numerical simulations by a global climate model with a surface energy balance theory, it is demonstrated here that urban surface and near-surface air temperatures are significantly more persistent than their rural counterparts in cities dominated by impervious materials with large thermal inertia. Further use of these materials will result in even stronger urban temperature persistence, especially for tropical cities. The present findings help pinpoint mitigation strategies that can simultaneously ameliorate the larger magnitude and stronger persistence of urban temperatures. 

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