Internal hydraulics of baffled disinfection contact tanks using computational fluid dynamics
Bibliographic record
Abstract
The present study focuses on understanding the internal hydraulics of baffled disinfection contact tanks for small drinking water systems using computational fluid dynamics (CFD). The emphasis of this study is to improve the hydraulic efficiency of disinfection contact tanks. In particular, the answer to the following key question was sought: for a given footprint of a contact tank, how does the hydraulic efficiency of the tank depend on the number and geometry of internal baffles? In an effort to address this question, high resolution two-dimensional (planar) simulations were performed to quantify the efficiency of a laboratory scale tank as a function of the number of baffles. Simulation results of the velocity field highlight dead (stagnant) zones in the tank that occur due to flow separation around the baffles. Simulated longitudinal velocity profiles show good agreement with previous experimental results. Analysis of residence time distribution (RTD) curves obtained for different number of baffles for a given footprint of a tank indicate that there may be an optimum number of baffles for which near plug flow conditions is maximized. This study highlights the increasing role and value of CFD in improving hydraulic design characteristics of water engineering structures. As a precursor to the CFD study, a focused literature review of disinfection systems was done to highlight the basic technologies and related applications. The review presented in this thesis summarizes details of small water treatment plants, disinfection and CT (where C is the concentration of disinfectant at the outlet of the disinfection system, and T is the time taken for the fluid to leave the system.) method, traditional tracer studies, tank design, and the development of numerical simulations. Following the review, the CFD model used for this investigation was validated using results from a previous case study of a large-scale water treatment plant in Canada. This initial CFD study is also used to highlight the uses and abuses of CFD in flow modeling and emphasize the importance of having adequate validation studies to complement the CFD work.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".