TY  - CHAP
A1  - Merkens, Torsten
A1  - Hebel, Christoph
T1  - Sharing mobility concepts – flexible, sustainable, smart
T2  - Proceedings of the 1st UNITED – Southeast Asia Automotive Interest Group (SAIG) International Conference
KW  - Sharing mobility
KW  - electro mobility
KW  - business models
KW  - mobility behaviour
Y1  - 2021
SN  - 978-3-902103-94-9
N1  - 1st UNITED-SAIG International Conference, 21-22 APR 2021, Chulalongkorn University, Thailand
SP  - 43
EP  - 44
ER  - 
TY  - JOUR
A1  - Blanke, Tobias
A1  - Hagenkamp, Markus
A1  - Döring, Bernd
A1  - Göttsche, Joachim
A1  - Reger, Vitali
A1  - Kuhnhenne, Markus
T1  - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates
JF  - Geothermal Energy
N2  - Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar fow and 60% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the fow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics.
Y1  - 2021
U6  - https://doi.org/10.1186/s40517-021-00201-3
SN  - 2195-9706
N1  - Corresponding author: Tobias Blanke
VL  - 9
IS  - Article number: 19
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Valero, Daniel
A1  - Schalko, Isabella
A1  - Friedrich, Heide
A1  - Abad, Jorge D.
A1  - Bung, Daniel Bernhard
A1  - Donchyts, Gennadii
A1  - Felder, Stefan
A1  - Ferreira, Rui M. L.
A1  - Hohermuth, Benjamin
A1  - Kramer, Matthias
A1  - Li, Danxun
A1  - Mendes, Luis
A1  - Moreno-Rodenas, Antonio
A1  - Nones, Michael
A1  - Paron, Paolo
A1  - Ruiz-Villanueva, Virginia
A1  - Wang, Ruo-Qian
A1  - Franca, Mario J.
T1  - Pathways towards democratization of hydro-environment observations and data
JF  - Iahr White Paper Series
Y1  - 2021
IS  - 1
SP  - 1
EP  - 9
PB  - International Association for Hydro-Environment Engineering and Research (IAHR)
ER  - 
TY  - JOUR
A1  - Hennes, Philipp
A1  - Laumann, Jörg
T1  - Ansatz der Drehbehinderung aus Koppelpfetten mit dünnwandigen kaltgeformten Z-Profilen
JF  - Stahlbau
Y1  - 2021
U6  - https://doi.org/10.1002/stab.202000104
SN  - 1437-1049
VL  - 90
IS  - 3
SP  - 158
EP  - 168
PB  - Ernst & Sohn
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Erpicum, Sebastien
A1  - Crookston, Brian M.
A1  - Bombardelli, Fabian
A1  - Bung, Daniel Bernhard
A1  - Felder, Stefan
A1  - Mulligan, Sean
A1  - Oertel, Mario
A1  - Palermo, Michele
T1  - Hydraulic structures engineering: An evolving science in a changing world
JF  - Wires Water
Y1  - 2021
U6  - https://doi.org/10.1002/wat2.1505
SN  - 2049-1948
VL  - 8
IS  - 2
PB  - Wiley
CY  - Weinheim
ER  -