Browsing by Author "Adhikari, Sanjay"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Hot Reservoir Variable Conductance Heat Pipe with Advanced Fluid Management(50th International Conference on Environmental Systems, 7/12/2021) Lee, Kuan-Lin; Tarau, Calin; Adhikari, Sanjay; Anderson, William; Kharangate, Chirag; Huang, Cho-Ning; Kamotani, YasuhiroA hot reservoir variable conductance heat pipe (VCHP) can offer a significantly tighter passive thermal control than a regular VCHP with a cold-biased reservoir. This attribute makes the hot reservoir VCHP an ideal thermal management device for future planetary landers and rovers and especially for the moon where surviving of the lunar night is energetically challenging. Since the hot reservoir cannot be wicked, it becomes a challenge to properly manage the presence of working fluid within the reservoir. To ensure a long-duration operation of the hot reservoir VCHPs in reduced gravity and in microgravity, advanced fluid management strategies and features must to be developed. Advanced Cooling Technologies, Inc (ACT) in collaboration with Case Western Reserve University (CWRU) is developing a reliable VCHP configuration under the NASA STTR program. The novel VCHP consists of a loop with well-engineered tubing configuration, that would generate a momentum induced continuous flow within the device. This induced flow would provide continuous maintenance of the NCG humidity in the reservoir as well as enable a much faster purging process (i.e. removal of moisture from the hot reservoir) if needed, significantly enhancing device�s reliability. The development of hot reservoir VCHP with advanced fluid management features will be presented in this paper, including both numerical and experimental efforts.Item Status of Development of a Thermal Probe for Icy Planet Exploration - I(50th International Conference on Environmental Systems, 7/12/2021) Adhikari, Sanjay; Chetty, Krishna; Tarau, Calin; Lee, Kuan-Lin; Hendricks, TerryTo Support NASA�s future Ocean Worlds Exploration missions, Advanced Cooling Technologies, Inc (ACT) is developing a thermal management concept for a radioisotope-powered ice melting probe. As presented in a previous paper [7], the concept includes several thermal features that allow for an efficient and reliable ice penetration. The development status for three of these features is presented in this paper. These three features are: 1. A pumped two-phase (P2P) loop to collect the waste heat from the cold end of the thermoelectric convertors and deliver it to the front vapor chamber with minimal internal resistance. 2. A front vapor chamber collects the heat from the P2P condenser and spreads the heat uniformly and effectively onto the inner side of the probe�s front for further conduction through the wall and into the environment. The same vapor chamber will deliver heat as needed to the variable conductance sidewall as needed 3. A variable conductance sidewall to prevent refreezing of the probe and also to allow for lateral melting as needed Under SBIR Phase II program, ACT developed detailed analytical models for the aforementioned thermal features. A unique P2P configuration, in which the fluid flow is aligned with the gravity, is modeled and designed. The model is also used to perform a working fluids trade study. A concept for the front vapor chamber is proposed to transfer heat from P2P to the melting head. Thermal calculations are performed for the variable conductance wall to evaluate the effect of heat loss from the side walls of the melting probe. This work has been performed under NASA Small Business Innovation Research (SBIR) Phase II Contract No. 80NSSC20C0178.