Full-Scale/Model Test Comparisons to Validate the Traditional Atmospheric Boundary Layer Wind Tunnel Tests: Literature Review and Personal Perspectives
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsComments for author File: 
Comments.pdf
Minor editing of English language is required.
Author Response
Reviewer 1
The manuscript systematically reviews comparisons between full-scale tests and model tests, focusing on validating the ABL wind tunnel simulation technique for various structures such as low-rise and high-rise buildings, bridges, large-span structures, and towers. Most literature suggests significant discrepancies between full-scale data and model results, often attributing these to technical issues in the ABL wind tunnel simulation technique. However, the authors, argue that inaccuracies in full-scale measurements may also contribute significantly to these discrepancies.
In general, the reference studies are well presented and discussed. However, The manuscript appears overly extensive and could be more concise by summarizing each reference study more briefly. Moreover, some minor revisions are needed to put more clarity to some aspects as summarized below;
1- The sentence mentioned below from abstract section line 21 is not very clear. Please consider revising the underlined part.
“differences in the root-mean-square acceleration between the full-scale measurements and the force balance model tests were non-negligible.”
Response: Thank you. The underlined phrase has been revised to “the root-mean-square (rms) values of the acceleration samples”. We suppose it is clear now. However, if the reviewer still disagrees, we will revise it again.
2- The “turbulence flow characteristic” phrase at line 26 should be revised as “turbulent flow characteristic”.
Response: Thank you. This terminology has been revised as suggested.
3- It would be beneficial to illustrate some sample results from reference papers to represent the measured data evaluation techniques. The paper contains no figures.
Response: Sorry that no figure has been added, as they are all subjected to the copyright issue. We have contacted many publishers of the reference articles for copyright, but found that the granting permission is difficult in most cases.
4- Does the phrase “smooth flow” in line 116-117 mean uniform flow?
Response: Yes, the smooth flow means the uniform flow. We have changed the terminology as suggested.
5- Both “story” and “storey” phrases has been used throughout the document. Please consider using one of the phrases to have a self-consistent text.
Response: Thank you. We have changed the phrase “story” to “storey” throughout the article for consistency.
6- Please consider revising the below-mentioned sentence (line 568-41) since it does not seem very clear;
“Besides, Cheng et al. [50] found that the model test conducted at the cooling tower’s design stage was conservative in use, since unfavorable wind pressure spectra and coherences are likely to be measured in the wind tunnel via the comparison.”
Response: To make the sentence clear, we have rephrased it as “Besides, Cheng et al. [50] found that the model test conducted at the cooling tower’s design stage was conservative for use, since comparing to full-scale measurement results, unfavorable wind pressure spectra and coherences were likely to be measured in the wind tunnels”.
7- It would be beneficial to describe the “rms acceleration” phrase presented in line 483.
Response: “Rms acceleration” means “the root-mean-square (rms) values of the acceleration samples”, which we have been explained throughout the manuscript.
8- Future research suggestions should include performing more accurate full-scale measurements.
Response: Yes, this suggestion of performing more accurate full-scale measurements has been added at the end of section 5 (see the part highlighted in red).
Reviewer 2 Report
Comments and Suggestions for AuthorsWell written manuscript with detailed review on field measurements and wind tunnel experiments with a sufficient number of references. The following comments:
The authors mention that "literatures concerning full-scale/model test cmoparisons were not systematically reviewed before" on lines 66-67 on page 2. This should be revised and clarified as the authors in section 3.2.1 describe full-scale and model test comparisons by Dalgliesh et al. in several studies cited in Table 1.
Section 5 Personal Perspectives should be rewritten as a general discussion taking into account the key points in the review of all papers (not only those by the authors) and recommendations for methodology and non-dimensional parameters for effective comparison of field measurements and wind tunnel tests.
Comments on the Quality of English LanguageQuality of English is good.
Author Response
Reviewer 3
Well written manuscript with detailed review on field measurements and wind tunnel experiments with a sufficient number of references. The following comments:
The authors mention that "literatures concerning full-scale/model test cmoparisons were not systematically reviewed before" on lines 66-67 on page 2. This should be revised and clarified as the authors in section 3.2.1 describe full-scale and model test comparisons by Dalgliesh et al. in several studies cited in Table 1.
Response: Thank you for the good suggestion. Dalgliesh et al. [4] indeed reviewed the full-scale/model test comparisons of wind effects on tall buildings undertaken by his group before 1980. However, except that, literatures concerning full-scale/model test comparisons were not systematically reviewed by others to the writers’ knowledge. Our original claim has been revised accordingly (see the part highlighted in blue).
Section 5 Personal Perspectives should be rewritten as a general discussion taking into account the key points in the review of all papers (not only those by the authors) and recommendations for methodology and non-dimensional parameters for effective comparison of field measurements and wind tunnel tests.
Response: In view of all literatures mentioned in this paper, Refs. [8-19,21-24,31-38,41-47] directly or obscurely sustain the contention that the full-scale/model test comparison should be the most reliable approach to validate the traditional ABL wind tunnel test. Most of these publications believe that performing more accurate full-scale measurements in future researches by addressing the uncertainty issue with the technique, which is usually associated with the nature of the realistic wind events (the unsteady and the non-stationary features), the testing errors related to the equipment and the human, the free choice of the data processing practice, etc, should be the recommendation for methodology for effective comparison of field measurements and wind tunnel tests. These have been explained in section 5 in the revised manuscript (see the part highlighted in green).
Reviewer 3 Report
Comments and Suggestions for Authors1. What were the limitations of wind tunnels used before the mid-1950s for civil engineering applications?
2. How do researchers deal with the challenges of meeting similarity criteria in wind tunnel experiments?
- 3. Why is scaling important in wind tunnel tests, according to the text?
- 4. According to Simiu and Scanlan, what features characterize the boundary layer in long wind tunnels?
- 5. According to Frandsen's 2001 study, what limitations of conventional experiments were highlighted in predicting full-scale structural behavior?
- 6. Can you identify any common challenges or discrepancies mentioned in the text across the different studies conducted on various bridges?
Comments on the Quality of English Language
The English language is generally acceptable, but minor revisions are needed.
Author Response
Reviewer 4
- What were the limitations of wind tunnels used before the mid-1950s for civil engineering applications?
Response: As indicated in the manuscript, before mid 1950s, wind tunnels with short working sections were used in civil engineering applications. However, the turbulence generated in these tunnels dramatically deviated from the simulation targets measured in the realistic ABL. In long wind tunnels, this issue has been partly addressed by meeting the basic simulation requirements (e.g., simulating the characteristics of the target flow). These explanations are underlined in the revised manuscript.
- How do researchers deal with the challenges of meeting similarity criteria in wind tunnel experiments?
Response: To meet the similarity criteria in wind tunnel experiments, researchers lay emphasis on a set of dimensionless numbers (Strouhal number, Rossby number, Reynolds number, Froude number, Prandtl number, Eckert number and Richardson number), and they believed that when these dimensionless numbers in the model test and the full scale agree well, the similarity issue with the wind tunnel test is well addressed. These are highlighted in the revised manuscript (see the part highlighted in purple).
- Why is scaling important in wind tunnel tests, according to the text?
Response: Wind tunnel tests occur at reduced geometric scales for obvious reasons of economy and convenience. Due to scaling, the similarities of the dimensionless numbers are jeopardized, as the flow events are different for different values of dimensionless numbers. Therefore, scaling is important in wind tunnel tests. Theses are explained in the revised manuscript (see the part highlighted in yellow).
- According to Simiu and Scanlan, what features characterize the boundary layer in long wind tunnels?
Response: According to Simiu and Scanlan, the features of long wind tunnels are: 1) the boundary layer is developed naturally over a long length; 2) the height of these tunnels can be adjusted to increase slightly with position downstream for the purpose of achieving a zero pressure gradient streamwise.
- According to Frandsen's 2001 study, what limitations of conventional experiments were highlighted in predicting full-scale structural behavior?
Response: According to Frandsen, the limitations of conventional experiments in predicting full-scale structural behavior reflect in the fact that the amplitudes due to the vortex-induced oscillations of the bridge are different between the model test and the full scale. Besides, lock-in phenomena observed are different for different cases. It is believed that limitations of conventional experimental methods for predicting full-scale behavior are due to scale effects.
- Can you identify any common challenges or discrepancies mentioned in the text across the different studies conducted on various bridges?
Response: Summarizing the above researches, the common challenges across different studies conducted on various bridges are identified as being vertical VIV amplitudes of long-span bridges measured using section models and aero-elastic models were much lower than those observed on the prototypes, and this is probably due to the scaling effects. These are explained in the revised manuscript (see the part highlighted in brown).
