基于冬季适老风环境模拟的寒地建筑形态优化方法

Optimization Method of Building Form in Cold Regions Based on the Simulation of Wind Environment Suitable for the Elderly in Winter

严寒地区冬季漫长而寒冷,人口老龄化严重,而老年人作为健康状况相对脆弱的群体,是寒地冬季室外公共空间的主要使用者,如何通过合理的建筑布局营造更为舒适的室外公共空间是亟待解决的科学问题。本文通过现场实测结合问卷调查、SPSS数理统计等方法实证研究冬季室外各种环境因素对老年人活动舒适度的影响机制。分析结果显示,在极低的室外温度作用下,风速成为影响老年人室外活动舒适度的主要因素,进一步结合TS-Givoni指标归纳出在严寒地区特殊气候条件作用下的室外风速限值。基于此对黑龙江省博物馆改扩建设计的多种空间形态风环境进行CFD模拟及评估优选,尝试对建筑设计形态优化提供理论方法指导。

The wind chill effect in severe cold regions is very significant,which greatly aggravates the uncomfortable degree of outdoor activities.Moreover,the effect of this harsh climate is long and the impact is deep,which makes winter the worst season of comfort in a year,and seriously limits people’s outdoor activities.Under the background of aging population,the problem of aging in severe cold regions is particularly serious.By the end of 2018,the proportion of the elderly population in Heilongjiang Province has reached 19.8%,which is about to form a deep aging society.As a group with relatively weak health status,the elderly have the strongest expectation for outdoor activities,and they are the main users of outdoor public space in winter.Due to their weak adaptability to environmental changes,higher requirements are put forward for the environmental quality of the space.How to create a more comfortable outdoor public space through reasonable architectural layout is an urgent scientific problem to be solved.Taking the elderly as the target population and the outdoor wind environment as the optimization object,through field measurement,questionnaire survey,CFD simulation and other methods,this paper tries to provide the basis for the shape design of outdoor public space of buildings in severe cold regions.In view of the different regions,times and activity states,people have different acceptance range of wind thermal comfort.In order to make the results more in line with the specific context of severe cold regions,the author carried out an outdoor activity comfort survey in Harbin in mid January 2020.The test sites were five leisure squares in Harbin where the elderly used more frequently.At the same time of questionnaire survey,NK4500 hand-held weather station and SM206 solar power meter were used for field measurement.A total of 204 questionnaires were distributed and 200 valid questionnaires were recorded.The effective rate was 98%.The data were processed and analyzed by SPSS software,and the influence mechanism of outdoor environmental factors(temperature,wind velocity,solar radiation intensity,humidity)on the activity comfort of the elderly in winter was studied.The evaluation standards of outdoor wind environment mainly include wind velocity ratio,wind velocity probability statistics and relative comfort.However,this kind of wind comfort only considers the wind stress and ignores the wind heat effect.It is relatively one-sided and general to evaluate the wind environment with these standards.The perception of the elderly to the external environment in winter in severe cold regions is mainly manifested as thermal comfort,and wind velocity is an important factor affecting thermal comfort.Therefore,combined with the outdoor thermal comfort evaluation standard,this paper summarizes the outdoor wind velocity limit under the effect of special climate conditions in severe cold regions,which fills the research blank in related fields.At present,the scale and space form of Heilongjiang Provincial Museum are more and more difficult to adapt to the current exhibition demand,so it is urgent to rebuild and expand.Echo with the existing buildings to form a dynamic and rich indoor and outdoor public space.In order to compare the advantages and disadvantages of different architectural space forms,this paper attempts to introduce the impact of architectural layout on outdoor public space wind environment in the early stage of shape design,so as to provide scientific basis for design decision.According to the requirements of the assignment,the building height is set as 12 m,and four kinds of space forms are preliminarily formed by taking whether or not to set the building opening and the opening position as the simulation variables.ICEM is used as the preprocessor for grid generation,and FLUENT is used as the wind environment simulation software.Finally,the simulation results are imported into TECPLOT for data processing and visual expression.The average wind velocity,the uniformity of wind field distribution and the distribution of wind comfort zone are used as the criteria to evaluate and optimize.In addition,in view of the full-time influence of building form on wind environment and the difference of users’demand for winter and summer wind environment,this paper takes the comfort degree of winter wind environment as the leading evaluation,and carries out the verification experiment combined with the summer meteorological data of Harbin.The comfort threshold and wind field distribution of outdoor wind in winter and summer are compared and analyzed in order to provide theoretical guidance for the optimization of architectural design form.Until now,there are still many deficiencies in the study of comfort evaluation index for different climatic regions and different users.Due to the limitation of research data and paper length,the wind velocity limit obtained in this paper as a universal evaluation index needs to be further studied.In this paper,the wind environment simulation evaluation is used as a criterion to optimize the architectural space form,which can provide evidence-based support for the scientific decision-making of architectural design.