An Exact Solution of the Inverse Problem in Heat Conduction Theory and Applications

In some industrial activities, the use of permanent heat transfer enhancements such as metal coating, pins, and grooves in cryogenic treatment is quite problematic. Such permanent heat transfer enhancers were replaced with temporary enhancers made of different crystalline materials, here focusing on NaCl, MgSO 4 ·7H 2 O, CaCl 2 ·2H 2 O, and C 6 H 5 Na 3 O 7 ·2H 2 O, which were used during quenching of the sample in the cryogenic liquid, i.e., nitrogen. The time required for sample cooling until the liquid nitrogen saturation temperature is reached decreases significantly when a crystalline coating is applied. The dependence of the cooling time on temporary coating creation parameters such as solution concentration, initial temperature of the sample, and solution spreading time is discussed.

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“…The sample surface temperature was deduced from the temperature in the sample center according to [24,25]:…”

Section: Methodsmentioning

confidence: 99%

Quench Pool Boiling with Temporary Crystalline Enhancers

et al. 2014

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“…The inverse heat transfer solution given for an infinitely long cylinder was used to calculate q i ″ and T i from the measured outer wall temperature readings. 29 Parasitic heat transfer from radiation and gas conduction are accounted for in the calculation of q i ″. The overall uncertainty in h and q i ″ in the film boiling heat transfer regime varies between 11 and 12.5% for all the tests.…”

Section: Quality Of Reduced Gravity Experimental Runsmentioning

confidence: 99%

The effect of reduced gravity on cryogenic nitrogen boiling and pipe chilldown

et al. 2016

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Manned deep space exploration will require cryogenic in-space propulsion. Yet, accurate prediction of cryogenic pipe flow boiling heat transfer is lacking, due to the absence of a cohesive reduced gravity data set covering the expected flow and thermodynamic parameter ranges needed to validate cryogenic two-phase heat transfer models. This work provides a wide range of cryogenic chilldown data aboard an aircraft flying parabolic trajectories to simulate reduced gravity. Liquid nitrogen is used to quench a 1.27 cm diameter tube from room temperature. The pressure, temperature, flow rate, and inlet conditions are reported from 10 tests covering liquid Reynolds number from 2,000 to 80,000 and pressures from 80 to 810 kPa. Corresponding terrestrial gravity tests were performed in upward, downward, and horizontal flow configurations to identify gravity and flow direction effects on chilldown. Film boiling heat transfer was lessened by up to 25% in reduced gravity, resulting in longer time and more liquid to quench the pipe to liquid temperatures. Heat transfer was enhanced by increasing the flow rate, and differences between reduced and terrestrial gravity diminished at high flow rates. The new data set will enable the development of accurate and robust heat transfer models of cryogenic pipe chilldown in reduced gravity.

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“…Considering 1D transient boundary value inverse problem in a flat slab Burggraf obtained an exact solution in the case when the time-dependant temperature response was known at one internal point, (Burggraf, 1964 …”

Section: Burggraf Solutionmentioning

confidence: 99%

Inverse Heat Conduction Problems

Grysa¹

2011

Heat Conduction - Basic Research

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An Exact Solution of the Inverse Problem in Heat Conduction Theory and Applications

Cited by 286 publications

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Quench Pool Boiling with Temporary Crystalline Enhancers

Quench Pool Boiling with Temporary Crystalline Enhancers

The effect of reduced gravity on cryogenic nitrogen boiling and pipe chilldown

Inverse Heat Conduction Problems

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