|
| Lockyer (1984) | Jiang et al. [64] | Roelcke et al. [56] | Study conditions | Aim | Important improvements | Reference |
|
| X | | | (i) CO2 was used instead of NH3
(ii) 3 trials were carried out: two of them in a greenhouse and the other in the field | Testing the reliability of the conventional sampling system. | Introduction of 20 sampling points on 4 branches, to avoid underestimation of the actual gas flux. | Loubet et al. [7] |
| | X | | (i) CO was used as a gas tracer
(ii) It was introduced below a water surface, using a single point or a linear manifold | Determination and improvement of gas recovery rate. | The recovery rate was improved up to 92–102%, using a modified sampling chamber and tube configuration. | Wang et al. [66] |
|
| X | | | (i) 2 indoor experiments conducted at constant wind speeds of 0.5 and 1.0 m·s−1
(ii) An alkaline solution (3 L) containing ammonium sulphate was used as trap for each tunnel | Design, construction, and calibration of a revised wind tunnel | A new arrangement that allows each tunnel to be an independent unit, with an adjustable speed motor and a continuous air sampler. | Meisinger et al. [67] |
| | | X | (i) 5 field experiments were carried out measuring NH3 volatilisation with IHF and DTM, in winter and summer season
(ii) Urea was used as fertiliser | Calibration of DTM by means of comparison with IHF results. | Two different calibration equations:
ln (NH3fluxIHF) = 0.444 ln (NH3fluxDTM) + 0.590 ln (v2m) (winter season)
ln (NH3fluxIHF) = 0.456 ln (NH3fluxDTM) + 0.745 ln (v2m) − 0.280 ln (v0.2m) (summer season.) | Pacholski et al. [57] |
|
| X | | | (i) Laboratory experiments were conducted with an NH3 source tank
(ii) Mean wind speed of 0.1–0.4 m·s−1, while turbulence intensities of 11–33% | Studying and modelling the NH3 mass transfer in the wind tunnel. | NH3 mass transfer coefficient was modelled statistically, depending on wind velocity and turbulence intensity. | Saha et al. [68] |
|
| X | | | (i) 5 wind tunnel sizes were simulated using CFD
(ii) Inlet air velocity range is 0.1–0.6 m·s−1 | Studying the effect of wind tunnel sizes on NH3 emissions. | The effects of wind tunnel size were evaluated. In particular, wind tunnel height affects both velocity and concentration boundary layer thickness. | Saha et al. [69] |
| | X | | (i) 4 flow distribution devices were designed and compared using CFD
(ii) Inlet air velocities used were 1, 2.5, and 5 m·s−1 | Assessment of the best aerodynamic performances with different WT configurations. | The problem of air stagnation and flow recirculation inside the chamber could be solved introducing particular flow distribution devices. | Scotto di Perta et al. [70] |
|
