Inverse design of an indoor environment using a filter-based topology method with experimental verification

In order to create a healthy, comfortable, productive, and energy-efficient indoor environment, the computational fluid dynamics (CFD)-based adjoint method with an area-constrained topology method can be used to inversely design the optimal number, size, location, and shape of air supply inlets and air supply parameters. However, this method is not very mature, and the distribution of retained inlets is always scattered. To solve that problem, this investigation introduced a filter method that smooths the intermediate results during the inverse design process. Using a three-dimensional, non-isothermal, asymmetrical office with pre-set air supply inlets as an example, this study verified the performance of the proposed filter-based topology method. The verified method was then used to solve a multi-objective design problem and design an optimal indoor environment for a room. The results indicate that the proposed method was able to find the optimal number, location, and shape of air supply inlets and the optimal air supply temperature, velocity, and angle that led to a thermally comfortable, healthy, productive, and energy-efficient indoor environment. Finally, this investigation installed the optimal inlets in an environmental chamber to mimic the room. The measured air temperature, velocity, and mean age of air in several typical locations in the environmental chamber matched the CFD simulation results very closely.     

Inverse design of indoor environment using an adjoint RNG k‐ε turbulence model

The adjoint method can determine design variables of an indoor environment according to the optimal design objective, such as minimal predicted mean vote (PMV) for thermal comfort. The method calculates the gradient of the objective function over the design variables so that the objective function can be minimized along the fastest direction using an optimization algorithm. Since the objective function is controlled by the Reynolds‐averaged Navier‐Stokes (RANS) equations with the RNG k‐ε model during the optimization process, all the corresponding adjoint equations should be solved, rather than the “frozen turbulence” assumption used in previous studies. This investigation developed adjoint equations for the RNG k‐ε turbulence model and applied it to a two‐dimensional ventilated cavity and a three‐dimensional, two‐person office. Design processes with the adjoint RNG k‐ε turbulence model led to a near‐zero design function for the two cases, while those with the “frozen turbulence” assumption did not. This investigation has successfully used the new method to design a two‐person office with optimal thermal comfort level around the two occupants.     

Development of a fast fluid dynamics-based adjoint method for the inverse design of indoor environments

The computational fluid dynamics (CFD)-based adjoint method may be appropriate for the inverse design of indoor environments, considering both accuracy and efficiency, but a single design still requires tens of hours with the use of a personal computer. To speed up the inverse design process, this study evaluated four fast fluid dynamics (FFD) models in terms of solving the Navier–Stokes equations, integration with turbulence models, and solving the adjoint equations. This study implemented the FFD solvers in OpenFOAM and validated them for predicting steady-state and transient indoor airflow. This study then validated the FFD solvers for solving the adjoint equations and the FFD-based adjoint method for inverse identification problems and inverse designs in indoor environments. The results showed that FFD was 20 times faster than CFD in predicting transient indoor airflow, and similar computational accuracy could be maintained; the FFD-based adjoint method was 4–16 times faster than the CFD-based adjoint method in the inverse design process.     

Optimization of air supply location,size, and parameters in enclosed environments using a computational fluid dynamics-based adjoint method

Optimal design of an indoor environment based on specific design objectives requires a determination of thermo-fluid control methods. The control methods include the air supply location, size, and parameters. This study used a computational fluid dynamics- (CFD) based adjoint method to identify the optimal air supply location, size, and parameters. Through defining the air distribution in a certain area (design domain) as a design objective in a two-dimensional, ventilated cavity, the adjoint method can identify the air supply location, size, and parameters. However, the air supply location, size, and parameters were not unique, which implied multiple solutions. By using any of the air supply location, size, and parameters identified as boundary conditions for forward CFD simulations, the computed air distribution in the design domain was the same as that used as a design objective. Thus, the computing costs did not depend on the number of design variables.     

某大剧院多功能厅空调热环境数值模拟预测与分析

利用PHOENICS软件,模拟预测了该多功能厅夏季空调工况下的室内温度场和速度场.结合计算数据分析了其室内热环境特性,给出了设计方案调整措施.     

对带透明隔热材料构件热箱热环境的模拟

分析了带有ＴＩＭｓ双层窗及复合墙体的热箱的动态传热过程,建立了热环境的计算模型。模拟结果表明,由于ＴＩＭｓ具有良好的太阳辐射透过率及良好的抑制对流损失的能力,使得热箱内空气温度在不供暖工况下也能上升到理想值。推断ＴＩＭｓ在建筑节能领域具有广阔的应用前景。     

Study on optimum design method for pleasant outdoor thermal environment using genetic algorithms (GA) and coupled simulation of convection,radiation and conduction

Extensive research has recently been conducted into improving outdoor thermal environments in summer. In this paper, (1) an optimum design method is developed with genetic algorithms (GAs) and coupled simulation of convection, radiation, and conduction for comfortable outdoor thermal environments, and (2) in order to examine the validity of the proposed optimum design system, an apartment block space in an urban area is set up as an analysis target and the optimum arrangement of buildings and trees in two cases are analyzed for pleasant outdoor thermal environment design. For the optimum arrangement of trees, two different cases within the target area are examined to clarify the effect of different target areas (all open space or walkways) on optimization. For the optimum arrangement of buildings, in order to clarify the effect of the different positions of apartment blocks and building coverage ratio, three cases with different positions or building shapes in the target domain are examined. As a result, the optimum arrangements of the buildings are derived using GA and simulations for the three cases, and the validity of the optimum design method is confirmed.     

空调工程中的蓄冷技术──第四讲 蓄冷空调系统的初步设计

介绍了蓄冷空调系统的初步设计方法，给出了蓄冷空调系统的冷负荷、制冷机容量及蓄冷量的估算方法，最后简要介绍了蓄冷空调系统的经济评价方法。     

试论现代城市环境设计中的传统文化性

对城市环境的传统文化性进行了分析，提出了发展城市环境设计的个性特色的方法，通过对西安城市环境的研究，解决了怎样融合和继承传统文化的问题，以体现西安的个性特色。     

Parametric studies and evaluations of indoor thermal environment in wet season using a field survey and PMV-PPD method

Fanger's PMV-PPD is the most famous thermal sensation indices but it is too complex to be applied in practice. To obtain simple and applicable correlations, taking Qujing of Yunnan province, China, as example, a wet season (six-month) field measurement was conducted in a naturally ventilated residential room. Based on collected data, PMV indices were calculated by using Newton's iterative method. It is shown that the PMV values approximately vary from −1.0 to +1.0 and the indoor thermal environment is basically comfortable. Relationships of the parameters (indoor and outdoor air temperatures, mean radiant temperature, PMV and PPD) and indoor air temperature gradients (vertical and horizontal) were also studied by means of the linear regression and the quadratic polynomial fit techniques. Numerous correlations with high relativities have been developed. Moreover, the vertical and horizontal air temperature gradients range from 0.1 K/m to 0.85 K/m and from −0.208 K/m to 0.063 K/m in wet season. It is convenient to use these results to evaluate and assess the indoor thermal environment under similar climatic conditions. The results of this work enrich and develop the basic theory of the indoor thermal environment design and control.     

热湿工况下工位辐射空调的热舒适实验研究

为研究热湿工况下使用工位辐射空调的人体热舒适情况,在人工环境实验室内,通过改变环境背景温度来影响人体的热感觉,并采用热感觉投票(TSV)作为评价标准,重点研究了人体头部、躯干、上肢、下肢以及整体热感觉情况。实验结果表明,尽管背景环境参数超出舒适范围,但使用工位辐射空调能维持受试者的舒适状态,即背景温度稳定在28℃时,平均整体热感觉投票值低于+0.2;背景温度为30℃时,受试者热感觉仍能满足ASHRAE规范中规定的80%可接受范围要求。     

地区气候特征与气候适应性对节能住宅建筑热工设计的影响

以成都地区为例,从地区气候特征与气候适应性分析其对节能住宅建筑热工设计的影响,为节能住宅热工设计中的室内外气候计算参数的选择与确定,提供科学与实践的依据。     

居住建筑室内热环境低能耗营造的多目标设计方法

人居环境改善涉及重大民生问题,节能减排是国家重大战略。因此,有必要寻求合理的居住建筑设计方法,使设计方案既满足居民的室内热舒适需求又能降低建筑能耗。基于多目标遗传优化算法,建立能够对建筑设计方案进行优化、实现增加室内热舒适时间比例的同时降低建筑全年冷热负荷的居住建筑设计双目标优化模型。最后,以重庆典型户型为实例进行优化,优化后的设计方案建筑全年冷热负荷降低了47.74%,室内热舒适时间比例提高了3.94%,验证了模型的可行性和准确性。     

Enablers and barriers of the multi-user virtual environment for exploratory creativity in architectural design collaboration

Pioneering psychology and co-design research has highlighted the potential that multi-user virtual environment (MUVE) may help architects’ exploratory creativity that is a recursive search to discover an optimal match of novel and appropriate solutions. However, it has been not reported hitherto in what ways MUVE helps or obstructs architects’ exploratory creativity in individual and collaborative modes of collaboration. To investigate this issue, we compared MUVE and sketching media in face-to-face and remote collaboration modes, involving 22 pairs of architecture major students. Based on interview and video-observation, we discovered that (1) in MUVE, anthropomorphic avatars, which other media do not have, enabled individual and collaborative explorations to discover unexpected affordances of new solutions, with evaluation on physical properties and layouts of solutions. In addition, (2) co-presence with collaborator’s avatars enabled inspiration on new ways of problem-solving and puzzle-making through shared design processes and events, with co-evaluation on social aspects of design solutions. (3) Co-presence in a shared environment also allowed mutual co-exploration that promotes emerging creative solutions, with co-modification on design errors. As barriers of MUVE, (4) avatar’s immersion caused inconvenient perception to explore large-scaled environments and track collaborators’ different experiences, but the barriers were not reported in remote collaboration.     

纵向焊接铝合金柱设计方法研究

大多数结构用铝合金通常要经过热处理或加工硬化以得到比退火状态更高的力学性能。这种合金焊接后,焊接热会使焊缝附近局部区域(称为热影响区HAZ)强度降低。而对于钢结构,由于其热导率比铝材小得多,因此只有高强钢才可能产生强度降低的热影响区,而且其强度的降低没有铝合金显著,热影响区宽度也比铝合金小得多。这将使焊接铝合金柱的设计变得更为复杂。由于我国目前还没有关于铝合金结构的设计规范,为此本文通过试验研究及对已有试验数据的分析,并参考国外规范,提出了纵向焊接铝合金柱设计方法的建议,并将计算结果与试验结果进行比较,两者吻合较好,从而验证了建议设计公式的适用性。     

具有上部侧墙开口和顶部开口的大空间建筑室内热环境特性的比较

针对具有上部侧墙开口和屋顶顶部开口两种上部开口形式的大空间建筑,模拟了采用分层空调时不同工况下的室内温度场和速度场,分析了两种上部开口形式下喷嘴高度,上部开口面积、排风温度和排风量对室内热环境的影响。     

独立新风系统(DOAS)研究(2):设计方法

介绍了低温送风独立新风系统的组成及全热交换器、新风机组、末端设备、风道的设计计算，分析了其热湿平衡，给出了一个工程设计实例。     

量子粒子群优化算法在抗震工程系统中的应用

介绍了标准粒子群算法的基本思想,为了使粒子能够满足全局收敛,提出了量子粒子群算法,将量子粒子群算法应用到抗震工程系统的投资最优分配中,并建立了相应的优化模型,最后通过一个算例验证了该方法的效率和有效性。     

An investigation on the interaction of moment‐resisting frames and shear walls in RC dual systems using endurance time method

Reinforced concrete (RC) dual systems are composed of RC moment‐resisting frames (MRFs) and RC shear walls, where MRFs are barely designed to handle gravity loads. Investigations have demonstrated that shear walls exert negative effects on the upper part of MRFs. In this paper, the interaction of shear walls and MRFs is inspected using endurance time (ET) method. ET is a dynamic time history‐based pushover procedure in which structures are exposed to a set of predefined intensifying ET acceleration functions. In this method, seismic performance of the considered structure is assessed based on earthquake return periods; during which, required predefined seismic performance objectives are fulfilled. In this study, several buildings with RC dual systems were designed based on the conventional codes. Next, their nonlinear duplicates were generated for the application of the ET analysis. It was revealed that shear wall elements impose considerable rotational demands—exceeding the criteria established by ASCE41‐13—on the beams and columns, especially those located on the upper parts of the buildings. This paper puts forth and reviews certain methods to cushion the negative effects brought about by RC shear walls, along with a detailed discussion on their merits and demerits.     

Investigation on the impacts of different genders and ages on satisfaction with thermal environments in office buildings

This paper investigates the effects of occupant gender and age on thermal satisfaction in office environments. The data used for the analyses was collected from 40-sampled occupants and their workstations on 38 floors in 20 office buildings in the U.S. with support from the U.S. General Services Administration. The field measurements include data collection for air temperature, radiant temperature, temperature stratification, relative humidity and air velocity of the sampled workstations. Occupant satisfaction surveys were distributed to each occupant in the workstations measured, and the thermal attributes of building systems were recorded. The objective and subjective data sets support statistical correlation analysis between environmental qualities and user satisfactions.