COOL-COVERINGS. André Santos, The Netherlands Copyright Active Space Technologies

Transcription

1 COOL-COVERINGS André Santos, The Netherlands Copyright Active Space Technologies

2 Young and competent company Started in 2007 in Germany, in 2004 in Portugal Role Support scientific Institutions and SME Supply engineering services to hardware providers Develop new technologies and transfer technologies from and to space sector Mission Provide Thermo-mechanical Engineering expertise and support Design and manufacture support systems (test, transport, subsystems) Perform advanced R&D in thermo-mechanical technologies and methods

3 Engineering Definition of requirements Architecture Thermal Analysis Design and optimization Test & Verification Very extensive experience in scientific & optical instruments Software ESATAN-TMS, ESARAD, NASTRAN STAR-CCM+ - Fluids and thermal analysis with convection (instruments on planets with atmosphere, European projects such as COOL-COVERINGS)

4 Scope Develop a novel and cost-effective range of nanotech enabled insulation materials to improve building envelope energy efficiency, both in retrofitting and new constructions. Active Space Technologies GmbH s role Provide thermal engineering support Perform all necessary thermal analyses software chosen: STAR-CCM+

5 Inputs Demo building dimensions user building dimensions Location of building Geographical coordinates, time of the year Material properties of all components of the building: physical, thermal, optical. Density Thermal conductivity Specific heat (transient analysis) Emissivity vs. wavelength Reflectivity vs. wavelength Transmissivity vs. wavelength

6 Desired outputs Similitude analysis between Demo and user building (temperature difference day/night, thermal inertia, maximum and minimum temperatures) Continuous iteration study until design team reaches best combination of materials Demo Breathing holes User (Window (S)) Door (N) Window at East North façade

7 - Modeling CAD Software or Integrated STAR-CCM+ 3D-CAD Models? STAR-CCM+ 3D-CAD Model : Effective if future changings are foreseen External CAD software: Faster, part and assembly modeling Chosen option: Mixed External CAD software used to model building Import assembly to STAR-CCM+, create surroundings in STAR-CCM+ 3D-CAD Model A O A-A 80,5 TYP A

8 Environmental conditions: weather & sun Geographic coordinates: Air temperature profile (summer) Solar profile: Solar flux: Direct and diffuse (W/m 2 ), solar altitude, solar azimuth Sky temperature (radiation) and soil (Earth) temperature From STAR-CCM+ online manual Interpolation of real data: Temperatures, Solar flux, Solar azimuth, solar altitude, radiat. temperature as F n = f n (time).

9 Modeling 1 st step: Import building (*.x_t) from CAD software 2 nd step: Model environment with STAR-CCM+ 3D-CAD Model: earth + surrounding air (in&outlet) 3 rd step: Merging/imprinting final assembly (Outlet) (Inlet) Earth Air

10 Defining physical conditions Define boundaries/physical conditions/materials before generating the mesh: Define materials in material properties (Continua) Define model (ideal gas, implicit unsteady, K-Epsilon turbulence, Segregated flow, solar loads, 3D, surface-to-surface radiation, Multiband thermal radiation (visible till 0.4 µm and infrared 0.7 µm) Define inlet/outlet, wind speed Insert fan speed on holes - forced recirculation Temperature of the Earth, Environment F E = f E (time)), Radiation F R = f R (time) Sun properties (solar flux, azimuth and altitude) F S = f S (time) Surface optical properties for each surface: Emissivity, reflectivity, transmissivity for selected bandwidths (visible, infrared)

11 Mesh demo building Remeshed surface Holes: mesh refinement using STAR-CCM+ Volumetric controls Volume mesh Air Solid (wall) Prism layers

12 Define Solver and post processing Solver: Time step: 3600 s Iterations: Chosen graphic Plots: Boundary Irradiation on all external surfaces Temperature monitoring, average and maximum in all faces of the building and inside Geometry: check mesh and geometry Planar cuts ZoY, ZoX, XoY in order to monitor and check temperatures through the thicknesses Solar irradiation: To monitor if the solar angles are correct (e.g.. 15h east wall on shadow

13 user building New geometry from CAD software Larger air environment (user building 25 m length vs. 3m demo) Same external physical conditions Coarser mesh

14 Demo building: Temperature map at 18h Temperature + velocity: Up left: ZoY, 18h Up right: XoY 1.2 m height, 18h Bottom right: detail at XoY 2m height, 18h

15 User building: Temperature map at 18h Temperature + velocity: Up left: ZoY, 18h Up right: XoY 3 m height, 18h

16 Comparison demo building vs. user building temperatures Component Demo building User building Roof temp 25 (06h) 54 (14h) 17 (06h) 63 (16h) Wall N 17 (06h) 30 (15h) 19 (06h) 28 (14h) Wall S 17 (06h) 38 (15h) 21 (06h) 38 (14h) Wall E 17 (06h) 31 (14h) 20 (06h) 30 (14h) Wall W 17 (06h) 35 (16h) 20 (06h) - 34 (16h) T inside 20 (06h) 29 (19h) 25 (11h) 27 (21h)

17 Comparison demo building vs. user building temperatures Temperatures at 06h Temperatures at 18h

18 External: Client new inputs Update demo building stratigraphy (sandwich walls), new optical properties of the paints according to nano-paints Compare temperature change with emissivity and bandwidths change Internal: for more accurate and faster analyses Modify air environment from prism to semi-sphere using diameter as a parameter to improve accuracy with a symmetrical environment, improve analysis run-time Study hole fan speeds. What is the influence if the fan speed s on the temperatures inside Improve run-time analysis in user building (air environment is currently 100m long)

19 Contacts For further information, please visit our website André Santos Tel: +49 (0) Mobile: +49 (0) Fax: +49 (0) Rudower Chaussee Berlin Germany