Common Bulkhead Tank Design for Cryogenic Stage of an Indian Launch Vehicle

Indian Space Research Organization (ISRO) has been advancing in space technology with its cost-effective techniques. Currently, ISRO, in its cryogenic stages, uses truss type intertank structure, which induces large concentrated loads at the truss interfaces. As a remedial measure, works on closed intertank are being carried out by them, but this configuration will considerably increase the launch vehicle mass compared to truss type. Therefore, after a thorough literature survey, a Common bulkhead (CBH) tank seemed to be the best solution to the aforementioned problem. Detailed research on sandwich-type CBH has been carried out in this paper with the motivation of saving mass and height in launch vehicles. Suitable core and facesheet material were selected. A novel foam-filled honeycomb core is suggested in this work. Several comparisons in various CBH dome designs were carried out to reach for the best possible configuration and composition that can be used. MATLAB®, SolidWorks®, and ANSYS® were used in parallel for all computations dealing with design and analysis. A mass saving of approximately upto 490 kgs and a height reduction of upto 1.755 m was obtained with the final selected configuration with respect to the current GSLV configuration. These savings can add extra payload capacity to ISRO launch vehicles in their future missions.

Modification of Septic Tank for Sedimentation Optimization in the Public Toilet (Case Study at Wisdom Park UGM)

Septic tank with sedimentation and anaerobic processes in the same tank is commonly used as a domestic wastewater treatment technology in individual households and communal systems. Although simple to construct, such a system has some problems, such as effluent not meeting the quality requirement and blocking by trash and suspended solid before the second treatment chamber. This research aims to develop a new septic tank design that is simpler to construct and improve performance. The new design uses HDPE material, which is easier to build and standardized compared to the conventional concrete structure. The performance of the new design was compared to the conventional septic tank. The start-up process was monitored for flowrate, COD, TSS, NH3N, PO4-P parameters and evaluated against effluent standards. The study was conducted at public toilet facilities at Wisdom Park UGM and Sunday Morning Market. Results from the study show that the new design effectively improves effluent quality and overcomes the trash problem.

Heat and mass transfer of multicomponent gas mixtures in cryogenic tank of automotive equipment

The use of liquefied gas as a motor fuel for automotive equipment has both certain advantages and significant problems. The paper deals with the solution of one of the main problems, reducing the speed of the phase transition of liquefied methane in a cryogenic tank in the mode of drainage-free storage. In solving the above problem, the process of convective heat and mass transfer caused by the chemical and physical state of natural gas and the external heat flow was investigated. The two-phase state of the gas is unstable in the event of an increase in heat input from the environment, which causes an imbalance of pressure and temperature in the volumes of the liquid and gaseous parts of the gas and creates the risk of an emergency. To prevent the formation of critical gas pressure in a cryogenic tank, a method is proposed for calculating the phase transition of liquefied methane to determine the volume fraction of vaporized gas using equilibrium constants, which will allow developing an algorithm for the technological process of gas recirculation in a specially designed tank design. This will also allow you to choose the best option for a thermal insulation layer that can reduce the rate of penetration of heat from the environment and increase the period of drainage-free storage of liquefied natural gas by 1.5-2 times.

Experimental Validation of a Solar Powered Multistage Flash Desalination Unit with Alternate Storage Tanks

The fossil fuels that power conventional desalination systems cause substantial environmental impact. Solar desalination can satisfy critical water needs with only a minimal contribution to global warming. The current work presents an attractive new design suitable for regions with limited water resources and high solar radiation rates. This work is an experimental study of a newly designed, solar-powered, multi-stage flash (MSF) desalination plant. The design could address the need to increase the limited water resources in solar energy-rich areas. The prototype consists of a solar collector, an MSF unit, and a novel dual thermal storage tank design. In this prototype, preheated brine is directly heated by circulation through the solar collector. Two tanks serve the MSF unit; one tank feeds the MSF unit while the other receives the preheated feed water. The two tanks alternate roles every 24 h. The study was conducted in Taif, Saudi Arabia, throughout the month of September 2020. The results of the experiment showed that 1.92 square meters of solar collector area is needed for an average daily production of 19.7 kg of fresh water, at a cost of approximately $0.015 per liter.

Design guidelines for on-site stormwater detention

The city of Curitiba-PR has a municipal decree that establishes the criteria for the design of flood detention tanks. However, these guidelines do not guarantee minimum efficiency during operation, as it may vary depending on their base area, water depth and flow regulating orifice diameter. In this research, a design method was proposed, establishing some new criteria that relate impervious areas of the lots to the tank design parameters. The efficiency definition was established with the premise that the tanks should provide the return of flows from an impervious area to its pre-urbanization scenario. This reduction was established as 70% of the peak flow in the city of Curitiba-PR. Based on simulations of flow routing with the Puls Method, the optimum geometric characteristics (volume, area, water depth and orifice diameter) of the tanks were obtained to guarantee the decrease in the peak. Comparing the results obtained from the municipal legislation design, the new method provided n minimal efficiency and a decrease of 24% of the tank volume.

Effects of Surge Tank Geometry on the Water Hammer Phenomenon: Numerical Investigation

A surge tank, as one of the most common control facilities, is applied to control head pressure level in long pressurized pipelines during the water hammer occurrence. The cost-effective operation of surge tank is highly affected by its characteristics (i.e., surge tank diameter and inlet diameter of surge tank) and can effectively reduce the repercussion of water hammer. This investigation utilized the method of characteristics (MOC) in order to simulate the behavior of transient flow at surge tank upstream and head pressure fluctuations regime for hydraulic system of a hydropower dam. The various types of boundary conditions (i.e., sure tank, reservoir, branch connection of three pipes, series pipes, and downstream valve) were applied to numerically investigate the simultaneous effects of the surge tank properties. In this way, all the simulations of water hammer equations were conducted for nine various combinations of surge tank diameter (D) and inlet diameter of surge tank (d). Results of this study indicated that, for the surge tank design with D=6m and d=3.4m, head pressure fluctuations reached minimum level in the large section of pipeline here is surge tank upstream. Additionally, occurrence of water hammer phenomenon was probable at the initial section of pipeline.

Towards Absolute Dose Measurement In MRI-LINAC And GAMMA KNIFE®: Design And Construction Of An MR-Compatible Water Calorimeter

The purpose of this work was to design and build a portable 4⁰C stagnant Water Calorimeter (WC) for dual use in MRI-linac and Gamma Knife® in addition to conventional radiotherapy linacs. WC determines radiation energy absorbed in a sensitive volume absolutely and directly through measuring radiation-induced temperature rise (related to the medium’s specific heat capacity). To assist with the design process, several parameters involved in calorimeter tank design including tank dimensions, a variety of insulation material and thicknesses, unique cooling design structures to sustain WC at 4⁰C, as well as the calorimeter vessel design were simulated, and the results on heat gain/loss at the point of measurement was evaluated. Based on the optimizations, a calorimeter tank was built, and one single set of initial measurements in a conventional clinical linear accelerator was performed.