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Supercritical airfoil6/26/2023 The forum member "Glider" may have some more input, since gliders (sailplanes) have been the primary type of aircraft to successfully utilize laminar flow. They did, however increase the speed of the aircraft by delaying compressibility issues. I do want to point out, however, that the "laminar airfoils" used in WWII did not produce extensive laminar flow in practice (laminar flow turned out to be extremely sensitive to small variations in profile and smoothness - even flush rivets would cause turbulent airflow). This work has received funding from the National Energy Group Major Pilot Project -China ( GJNY2030XDXM-19-10 ) and the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no.I agree. The present work provides insights into the mechanisms of supercritical CO 2 heat transfer characteristics as well as practical guidance on the design and optimisation of relevant components. The FSRD distribution of fins is the optimum scheme among the three distributions of the modified airfoil fins channel because its comprehensive performance is 23 – 29% higher than that of the uniform distribution of fins and 2 – 7.6% higher than that of the FDRS distribution of fins. The differences of thermal-hydraulic performance among channels with uniform, FDRS, and FSRD distributions of fins can be explained with the field synergy principle. The match of the local dense distribution of fins with the region near the pseudocritical point could obtain better overall thermal performance in the modified airfoil fins heat exchanger. The results showed that the FDRS and FSRD distributions of fins can enhance heat transfer by improving the distribution uniformity of the temperature difference in the channel. The thermal-hydraulic performance of channels with different distributions of fins was compared under constant heat flux conditions and coupled heat exchange conditions. Based on the uniformity principle of the temperature difference field (TDF), two non-uniform distributions of fins, including the front-dense and rear-sparse (FDRS) and front-sparse and rear-dense (FSRD) distributions of fins, are proposed. The dramatic changes in the thermophysical properties of SCO 2 lead to uneven distributions of local heat transfer coefficient and local temperature difference along the channel, especially in the region near the pseudocritical point (0.99 < T b/ T pc < 1.02). In this work, the local thermal-hydraulic characteristics of SCO 2 in the modified airfoil fins channel were numerically investigated under conditions of m = 1.06 – 2.26 g/s, T in = 328.7 – 388.7 K, and q w = -50 kW/m 2 and -100 kW/m 2. The PCHE with modified airfoil fins has better comprehensive performance than PCHEs with zigzag channels and NACA 0020 airfoil fins and the optimisation of the modified airfoil fins heat exchanger is crucial to the performance improvement of the SCO 2 Brayton cycle system. The printed circuit heat exchanger (PCHE) is an ideal candidate as a regenerator and pre-cooler in the SCO 2 Brayton cycle due to its advantages of high compactness and efficiency. ![]() ![]() The supercritical pressure CO 2 (SCO 2) Brayton cycle is an efficient and compact power cycle that has promising potential in solar and nuclear power generation systems.
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