Detailed multi-node model of human physiology to predict dynamic thermal comfort responses

Transcription

1 Detailed multi-node model of human physiology to predict dynamic thermal comfort responses Dusan FIALA, PhD University of Stuttgart Germany

2 Contents Model Systems Validation examples Physiological modelling of thermal comfort

3 Model of human thermoregulation: Passive System

4 Model of human thermoregulation: Active System

5 - Active System: System coefficients [g min K ] b sw,sk - coefficient T sk,m,t [K] Regression bsw,sk coefficient b - sh,sk [W K ] T sk,m,t [K] Regression b sh,sk coefficient bdl,sk [W K ²] T sk,m,t [K] Regression b dl,sk coefficient bdl,hy [W K ²] coefficient bcs,sk [K ] [g min K ] b sw,hy coefficient T hy,t [K] Regression b dl,hy T sk,m,t [K] Regression b cs,sk T hy,t [K] Regression b sw,hy

6 evap. heat loss [W] Transient conditions mean skin temp. [ C] C Ta=Tw=48 C 8 C time [min] 37 rectal temperature [ C] rectal temp. [ C] evaporation [W] Ta=43 C Ta=7 C Ta=43 C mean skin temp. [ C] metabolism [W] experiment simulation Ta=Tw, va<.m/s, rh=3%, Icl=.clo, act=met, n= time [min] experiment simulation Stolwijk model Ta=Tw, va=.m/s, rh=3%, Icl=.clo, act=met, n=3

7 Validation: Principal human thermal behaviour metabolism [W] mean skin temp. [ C] rectal tem mp. [ C] evaporation [W/m²] mean skin temp. [ C] rectal T [ C] ambient temperature [ C] experiment: mean ± SD simulation t=6min, Tw=Ta, va=.3m/s, rh=5%, act=.8met, Icl=.clo, n= ambient temperature [ C] experiment : mean ± SD simulation t=6min, Tw=Ta, va=.m/s, rh=3%, Icl=.clo, act=met, n=3

8 Radiant Temperature Asymmetry 4 Temperature e [ C] Neck Pos Forehead Foot instep Leg LowPost Mean Skin Temp Rectal Temp Mean Rad Temp Air Temp Sim Radiant temperature asymmetry [K]

9 Field measurements Hiking : Boundary conditions Air temperature Wind speed..4. air temperature [ C] Simulation air speed [m/s] Solar Radiation Activity / Metabolic rate 9 7 Solar Radiation [W/m] Qmet [W] Simulation

10 Field measurements Hiking : Body temperatures 4 Mean skin temperature 4 Body core temperature 39 Tskm [ o C] 3 3 Sim. Sim. 3 Trectal [ o C] 37 Sim. Sim Skin temperature: Chest Skin temperature: Back 4 4 Tsk, chest [ o C] 3 3 Tsk, back [ o C] 3 Sim. Sim

11 Field measurements Hiking : Skin temperatures Tsk, arm [ o C] Skin temperature: Upper arm Sim. Sim. 3 Tsk, forearm [ o C] Skin temperature: Lower arm Sim. Sim. 3 Tsk, leg [ o C] Skin temperature: Upper Leg Sim. Sim. 3 Tsk, calf [ o C] Skin temperature: Lower leg Sim. Sim. 3

12 Field measurements Hiking (Test VI). Air temperature 35 Solar Radiation air temperature [ C] Solar Radiation [W/m] Skin temperature: Chest Mean skin temperature 4 4 Tsk, chest [ o C] 3 3 Sim. Sim. 3 Tskm [ o C] 3 3 Sim. Sim

13 Thermal Comfort: modelling approaches Existing models Nevins et al.: Fanger Model (iso773): TS = f (T o,rh) TS = f ( Q), i.e.heat flux Gagge Model: TS = f (T a,p a ) f (wsk) Nishi et al Model: TS = f (Tsk) Aser & Hsu Model: Question: TS = f (KS) } What physiological parameters do actually govern the human Thermal Sensation? Physilogical approach

14 Simulation and analysis of TC experiments Thermal Sensation TSV = f (Sw) TSV = f (Qsk) Thermal Sensation msw [g/min] Qsk - Qsk, [W] Thermal Sensation TSV = f (Thy) TS = f (Tsk) Thermal Sensation Thy - Thy, [K] Tsk,m - Tsk,m, [K]

15 Effect of body core temperature (exercising subjects) φ = gsk x ghy [ ] [ ] gsk 3 ghy Tsk,m - Tsk,m, [K] Thy - Thy, [K]

16 Dynamic components of Thermal Sensation Therma al Sensation - - Dynamic Thermal Senstation (DTS) Ta=8 C Ta=8 C Ta=8 C (8.4 F) (64.4 F) (8.4 F) f + ( ) dt sk,m f ( ) dt - dt sk,m dt time [min] experiment static TS dynamic TS (DTS)

17 Validation examples: Ramps Therm mal Sensation [ ] Air tem mperature Ta [ C] time [min] experiment DTS (Ta) Tw=Ta va=.m/s Tdew= C Icl=.5clo act=.met n=

18 Validation examples: Step changes in Ta Therm mal Sensation [ ] time [min] exp.: To = 7/ C (sw/n) exp.: To = /7 C (N/s C) DTS: To = 7/ C DTS: To = /7 C

19 Validation examples: Transient exercise Therma al Sensation level [met] activity experiment simulation (activity) time [min] Ta =Tw = C va =.m/s rh = 5% Icl=.clo n =

20 Validation examples: Periodic changes Therm mal Sensation [ ] time [min] exp.: males exp.: female DTS (Ta) Air tem mperature Ta [ C] Tw=Ta va=.5m/s rh=5% Icl=.7clo n=

21 Thank you for listening